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SPECTRUM ANALYSISBY
JOHN LANDAUER,Member ofthe Imperial
LL.D.,Naturalists.
German Academy of
AUTHORIZED ENGLISH EDITIONBY
J.
BISHOP TINGLE,Chicago,III.
PH.D.,
F.C.S.,
Instructor of Chemistry in the Lewis Institute,
FIRST EDITION.FIRST THOUSAND.
NEW YOR K.JOHN WILEY & SONS. LONDON CHAPMAN & HALL, LIMITED.:
1898.
Copyright,BYJ.
1898,
BISHOP TINGLE.
ROBERT DROMMOND. ELECTROTYPRR AND PRINTER, NEW YORK.
AUTHOR'S PREFACE.THIS work originated as a reprint of an article on Spec" trum Analysis recently contributed to Fenling-Hell's Neues " it was published as a sepaHandworterbuch der Chemie rate book at the request of a number of competent authorities, but not without some hesitation on the part of the author,;
because in treating a subject in an encyclopedic article regard
must be paid to the whole plan and scope of the work, whilst in a separate book the author is quite independent. The favorable reception accorded to the book whenpublished givesrise
to the
hope that shortcomings
arising
some extent counterbalanced by a origin fulness of contents brought together in small space, by the strictly historical treatment of the subject adopted throughfromits
are to
out the book, by tolerably full bibliographical references, and by the care which has been bestowed on the numerical tablesIn order to secure a degree of uniserving for reference. formity hitherto wanting, the older measurements have beenrecalculated so as to bring system of wave-lengths.
them
into accord with
Rowland's
THE AUTHOR.BRAUNSCHWEIG,1898.iii
ABBREVIATIONS.following abbreviations have been used in the bibliographical references:
THE
A. B. A.
=
Abhandlungen
Koniglichen Akademie der VVissenschaften zu Berlin.et
der
A.B.C.
c.
p.
A. R.N.r.
C.
= = = =
Annales de chimieChemical News.
de physique.
British Association Reports.
Comptes rend us hebdomadaires des Seancesde 1'Academie de Sciences, Paris.Nature.
N. N. A. S.P.
= U ==
Nova ActaPoggendorff's
Regiae
Societatis
Scientiarum
Upsaliensis.
A.
Annalen
der
Physik
und
Chemie.P.P.
M. M.
P. S.
= = = = = = =
Philosophical Magazine. Proceedings of the Manchester Literary andPhilosophical Society.
P.
R. S. R. S. E.T.
Proceedings of the Royal Society.Proceedingsburgh.of
P.
the
Royal Society,
Edin-
P.
Philosophical Transactions.
P. T. E.
T. R. S. E.
Philosophical Transactions, Edinburgh. Transactions of the Royal Society, Edin-
W. A.
=
burgh.
Wiedemann'sChemie.
Annalen
der
Physik
und
TRANSLATOR'S PREFACE.
curriculum
claim of spectrum analysis to a place in a chemical is steadily obtaining increased recognition, and its is generally admitted both for students importance preparingfor teaching,
THE
calits
work.pursuit
who wish to engage in technologiThe subject may rightly demand a wider field since furnishes so many opportunities for an excellentandfor those
training in accuracy of observation and manipulative skill that it might, with great advantage, find place in a general sciencecourse.
The expense
is
by no means
prohibitive,
and
is
almost entirely confined to the first cost of the instruments, which, with proper care, last for years, and even with the cheaper and smaller ones, such as Browning's "Students'Spectroscope," which costs about $30, much interesting work can be done and valuable discipline obtained.
Of the works on spectrum analysis hitherto published in English, none are suitable as text-books, either on account of their size and consequent cost, or from the manner in whichthe subjectIt isis
presented.this little
hoped that
book may,
in
some degree, sup-
ply this lack.
There has been no attempt to treat the subject exhaustively, but rather to indicate the more salient points of theory, etc., leaving it to the teacher to complete and expand themat his
own
discretion.it
No
doubt
would be well
if
all
students were compelledvii
to take a course in general physics before attacking chemistry,
Vlll
TRANSLATOR'S PREFACE.
but at present this is a state of things not realized in practice; to those who have followed such a course the physical sectionbut it may serve to call of the book should be superfluous the attention of the others to matters on which they should;
obtain more instruction.
The
tables of wave-lengths will,
it
is hoped, be useful in the practical work which would probThe posiably constitute the greater portion of the course. tion of the more prominent lines and bands can, by their
help, be at once ascertained, identification facilitated.
and
their actual occurrence
and
LEWIS INSTITUTE,CHICAGO,ILL., Dec. 1897.
CONTENTS.
CHAPTERINTRODUCTORYHISTORICALi.
........2.
I.
PAGEr
Introductory,
Historical,8.
Bibliography of
Works on
Spectrum Analysis,
CHAPTERPHYSICAL PROPERTIES OF LIGHTWave-length,persion,16. 14.
......Prisms,13.
II.
nDis-
ii.
Reflection; Refraction, 12.
Abnormal Dispersion, 15. Pure Spectra; Gratings, Diffraction, 17. Comparison of Diffraction and Refraction19.
Spectra,
CHAPTERSPECTROSCOPES..-
III.... .
.
.
k
.20
Spectroscopes with Angular Vision, 20. scopes, 28. Grating Spectroscopes, 31.
Direct-vision Spectro-
CHAPTER
IV..
SPECTROSCOPIC INSTRUMENTS FOR SPECIAL PURPOSES
.
.
.35
Kriiss' Universal Spectroscope, 38. Spectrometer, 35. SpecSolar and trophotometer, 39. Sorby's Microspectroscope, 40. Stellar Spectroscopes, 41. Stellar Spectrometers; Spectrographs, Rowland's Concave Grating Spectrograph, 45. 43.
CHAPTERSPECTROSCOPIC ADJUNCTS
V.51
Flame Spectra, 51. Electric Arc, 54. Electric Spark, 55. Geissler or Pliicker's (Vacuum) Tubes, 58. Observation of the InvisibleRegions of the Spectrum; Ultra-violet,vation of Absorption Spectra, 63.Scales, 65.60.
Infra-red, 61.
Obser-
Measuring Appliances andix
Drawings
of Spectra. 68.
X
CONTENTS.
CHAPTEREMISSION-SPECTRALine Spectra,71.
VI.PAGE
69
Lockyer's Long Current, 75. Absorption Spectra; Kirchhoff's Law, 76. Influence of the Temperature and the Physical State of Substances, 77. Influence of the Optical Density; Influence of the Solvent, 78. Fluorescence and Absorption, 79. Relationship between the Linesof an Element. 80.
Influence of Temperature and Pressure, 72. Influence of Magnetic and Short Lines, 73.
Relationship between the Spectra of Differ-
ent Elements, 87.
CHAPTERSPECTRA OF THE ELEMENTSUnit of Measurement,Reactions, 95.96. 92.
VII.
.92Scale of Colors(in;
Spectra of the Elements
Delicacy of Spectrum Alphabetical Order),
CHAPTERABSORPTION SPECTRA
VIII.174
Absorption by Gases and Liquids, 175. Different Salts of the same Colored Base or Acid, 177. Relationship between Molecular Structure and Absorption Spectrum, 178. Absorption in theviolet, 182.
Visible Portion of the Spectrum, 179. Absorption in the Absorption in the Infra-red, 184.
Ultra-
CHAPTERTHE SOLAR SPECTRUMThe FraunhoferSun, 190.Lines, 186.
IX.186
The Chemical Composition
of the
Rowland's Table of Wave-lengths of the Fraunhofer
Telluric Lines of the Solar Spectrum, 201. Limits of Lines, 191. the Investigation, 202. Physical Condition of the Sun, 203. Solar
Nucleus
;
Photosphere
;
Sun-Spots. 204.
Solar Faculae205.
;
Reversing207.
Layer
;
Chromosphere and Prominences,
Corona,
CHAPTEROTHER CELESTIAL BODIESFixed Stars, 208.ites
X.208
Planets and Moon, 209.;
Comets;
Meteor-
and Shooting Stars
Light; Lightning, 211.
Aurora Borealis; Zodiacal Nebulae, 210. Displacement of the Lines, 212.
SPECTRUM ANALYSIS.CHAPTERINTRODUCTORY.SPECTRUM ANALYSISmeansofis
I.
HISTORICAL.
which
it is
a chemico-analytical method by possible to determine the constituents of
a substance, by observing the refraction (dispersion), or the Its further development offers a diffraction of light-rays. means of investigating the molecular structure of matter.
produced when light-rays are refracted is termed a spectrum. White-hot solid bodies emit rays of all refrangibility, and give a continuous spectrum; glowing gases or vapors emit rays of definite refrangibility, and therefore
The image which
is
yield a discontinuous spectrum consisting of bright lines which are characteristic of each substance, and which consequentlyit occurs alone, or together the rays from a white-hot solid pass through a colored medium some of them are retained giving an absorption spectrum, which varies with the chemical
serve for
its
identification
whether
with other bodies.
When
composition of the medium.far
Spectra-reactions are characterized by an extreme delicacy exceeding that of chemical tests, and therefore theirled to the discovery of a
employment has
number
of
new
elements which occur only in small quantity. Since the distance of the source of light has little effect on a spectrum, the method can be employed for the investigation of celestial
2
SPECTRUM ANALYSIS.it
bodies:
has extended our knowledge of their nature to an1
extent which was previously entirely unattainable.hoff
Spectrum Analysis was founded by Kirchand Bunsen in 1859, an d subsequently developed. Other observers had previously noticed spectrum lines, and had suggested the application of spectroscopic observations to chemical analysis, but their efforts were fruitless, as at that time it was not certain whether the bright lines of a glowing gas were solely dependent on its chemical composiThe sodium reaction was particularly misleading as it tion. was often observed when the presence of this metal was not suspected, and was therefore variously ascribed to sodium, to The yellow sodium flame was first sulphur, or to water. Thomas Melville in 1752, but he was unable to noticed byHistorical.2
determine
1822 investigated the spectra of many colored flames, particularly those given by strontium, copper, and -boric acid, and in 1827 showed that by this means the substances giving the colors could beits
origin.
John Herschel
3
in
recognized even when present only in extremely small quanFox Talbot 4 in 1826 expressed himself still more tity. definitely, stating that if his theory that certain bodies gavecharacteristic lines should prove to be correct, then a glance at the prismatic spectrum of a flame would suffice to identify
substances which would otherwise require a tedious chemical In 1834 he correctly described analysis for their detection.the lithium and strontium spectra, and again pointed out thatKopp, Entwickelung der Chemie in der neuren Zeit (Miinchen, 1873), Kirchhoff, Zur Geschichte der Spectralanalyse. P. A. 118, 102. Brewster, C. r. 62, 17. Kahlbaum, Aus der Vorgeschichte der
1
pp. 215, 642.94,
{Braunschweig,2 8
Rosenberger, Geschichte der Physik, 3 Spectralanalyse (Basel, 1888). P. M. [4] 25, 250. Stokes, N. 13, 188. Talbot, 1890). P. R. S. E. 7, 461.Edinb. Phys. andLit.
Essays, 2,
12.
T. R. S. E. (1823) 9.
P. A. (1829) 16.P.
On
the theory of light (Lon3.
don, 1828) 4 Brewster's Journ. of Sci.
5.
M.
(1833) [3] 3, 35; (1836), 9,
INTRODUC1 'OR Y. HIS TO RICA L
.
3
such optical methods permitted of the identification of these elements with a minimum quantity of substance, and with anexactitude equalling, if not excelling, that attained by any Doubt was, however, cast on this conclusion other process. by contradictory statements in the same communications, and
the method of analysis was rendered fundamentally dubious, because, in opposition to Herschel, Talbot maintained that the reactions could be produced by the simple presence of thesubstance in the flame,its
volatilization not being necessary.
1845 an investigation on tne spectra of the alkali metals; diagrams were given, but the results did not constitute any great advance, as he had
W.
A. Miller
1
published in
employed a luminous flame, and was therefore unable to determine what was characteristic of any particular metal. In 1856 Swan definitely proved that the yellow line which is almost always present is peculiar to sodium compounds, and that the frequency of its occurrence is due to the almost In his work on the universal distribution of sodium salts.8
prismatic spectra of the hydrocarbons Swan showed that the lines observed are constant in position; he thus made a valuable contribution towards the solution of the question as to whether the bright lines of a glowing gas are exclusively
dependent on its chemical composition. The definite and general answer to this problem was, however, not given by Swan, but by Kirchhoff and Bunsen. The spectra of the electric spark had been under observation simultaneously with those of flames; Wollastondetected a large number of bright
3
lines, but without offering He was also the first to describe clue to their origin. any the dark lines in the solar spectrum, and he improved the
apparatus employed by substituting a narrow slit for the circular opening which Newton had used to admit the light.1
2 3
P. M. [3] 27, 81. B. A. R. 1845T. R. S. E. 3, 376; (1857)21,353. P. T. 1802. p. 365.
4Fraunhofer1
SPECTRUM ANALYSIS.
was scarcely more successful than Wollaston so far as the origin of the bright lines was concerned: his fame rests on the discovery of the diffraction grating, the measurement of wave-lengths which its use permitted, and on the observation of the dark lines in the solar spectrum which bear He drew 350 of these, and finding that they his name. varied from those observed in stellar spectra, he concluded that they originate in the sun and stars, and are not due to 2 Wheatstone in 1835 found that the earth's atmosphere.with the use of different metallic electrodes the spectra vary, but they remain constant no matter whether the dischargetakes place in air, hydrogen, or in a vacuum; he therefore concluded that the metal is volatilized, but not burnt, by the
He published drawings of the spectra passage of the spark. of sodium, mercury, zinc, cadmium, bismuth, tin, and lead,and recommended the method
The
spectra
of
various
for analytical purposes. metals volatilized in air were3
in 1849; he studied, although less thoroughly, by Foucault also observed the dark /7-line, since known as the reversed
sodium line, but failed to draw the important conclusion from this which Kirchhoff subsequently made. Masson, who improved the method of working, using condensers charged by induction-currents, investigated the spark-spectra of iron, tin, antimony, bismuth, copper, lead, cadmium, and carbon; in all these cases he noticed that the lines due to moist air were present, although he was ignorant of their origin. This was indicated by Angstrom's important work published in He showed that the lines which occur in the space 1853. between the electrodes are due to air or to any other gas4 a1
Denkschriften der Miinchener Akad., 1814, 1815; Gilbert's Ann. 74,B. A. R. 1835.C. N. 3, 198.P.
3372
M.
[3] 7.
3
Institut. 1849, p. 44.
4b
A.
c. p.
(1851) [3] 31, 295.p. 335.
K. Vetenskaps Akad. Handl. (Stockholm, 1853),
P. A. (1855)
94, 141.
INTRODUCTORY. HISTORICAL.
5
which may be present, whilst those close to the electrodes are Angstrom also drew and described the given by the metals. of a large number of metals and non-metals, and spectra almost discovered the relationship between the emission and absorption of light, since he stated, in accordance with a suggestion of Euler, that at a common temperature bodies absorb the same vibrations which they are capable of producing.
In 1858 Pliicker commenced his investigations of the spectra produced by the passage of an electric current through highly He found that the elementary gases, or rarefied gases.1
the constituents liberated fromacterized
compound
gases,
are char-
by
bright lines.8
van der Willigen, who in electrodes moistened with a salt solution give the spectrum of the salt, and that it is therefore unnecessary to use theorder to obtain its spectrum. In the same year and Bunsen published their work " Chemische Kirchhoff Analyse durch Spectralbeobachtungen" their results were
Similar work was pursued by 1859 a l so showed that platinum
metal
itself in
3
;
obtained to some extent independently of previous investigators who, whilst frequently on the right path, had failed to reach the goal. They reduced spectral phenomena to achemical-analytical method, and definitely proved that the bright lines produced by a glowing gas are dependent only
This law still forms the basis chemical composition. but their second proposition has been of spectrum analysis,its
on
in
subsequently considerably modified; it states that the manner which the constituents of a substance are combined is with-
out influence on their spectra, and that these are also almost entirely unaffected by the temperature and pressure of the vapor. After Roscoe and Clifton had called attention to the difference between the spectrum of an element and those of4
its
compounds, A. Mitscherlich1
*
showed,
in 1863, that
every
*
P. A. 103, 88; 104, 113, 622; 105, 67; 107, 77, 415. 3 P. A. 106, 610; (1859) 107, 473. P A. 110, 167.
4
P.
M.
P. S.
1862.
5
P. A. (1863) 121,
3.
6
SPECTRUM ANALYSIS.
compound has its own peculiar spectrum, and that the exhibition of identical spectra by the various salts of an element In their first is caused by these undergoing dissociation.of the metals of the alkalis
communication Kirchhoff and Bunsen described the spectra and alkaline earths, and showed the great delicacy of the method, which permits of the recognition of substances
present in quantity far too small for detection by the ordinary processes; they also pointed out the great extension which it gives to our knowledge of thedistribution of the elements,
when
and indicated that
it
would
The correctprobably lead to the recognition of new ones. ness of this view has been proved by the discovery of caesium, rubidium, thallium, indium, gallium, and many metals of therare earths,all
by meansof
of
spectrum analysis.1
The developmentimpulse fromits
spectrum analysis received a special application to astronomy. Kirchhoff proved
between the emissive and absorptive powers
mathematically that for every ray of light the relationship of all bodies is
alike at uniform temperatures; this explained the origin of the Fraunhofer lines, and led to the investigation of the chemical
The discovery composition of the sun and its atmosphere. of this law of exchanges induced Kirchhoff to prepare moreexact drawings of the solar spectrum, and to accurately compare the positions of the Fraunhofer lines with those in thespectra of
many
terrestrial substances.scale, as did also
He employed2
for this
purpose an arbitrarythese observations.
Huggins, who extended
belongs the credit of subthe wave-length for the scale as a means of determinstituting ing the position of the lines, and his measurements, and atlas of the solar lines, remained for twenty years the foundationo
To Angstrom
3
of
all
spectroscopic investigations.27, 1859.
Angstrom's work was
1
Monatsber. Berl. Akad., Oct.P. T. (1864) 154.
2
3
Recherches sur
le
spectre normal du soleil avec atlas de 6 planches.
Upsala, 1868.
IN TR OD UCTOR Y. HIS TO RICA L.
f
confined to the visible portion of the spectrum; it was comresearches on the ultra-violet, and by pleted by Cornu's'
Langley's and Abney's on the infra-red. After Angstrom's death, Thalen showed that the metre he had employed was incorrect, and that consequently his wave-length determinaThis was confirmed by Muller and tions were too small.4
2
3
5
Kempfcarried
in
1886: their measurements of 300 solar lines were
out with great care, and became the basis of the Potsdam system. All these determinations were, however, 6 exceeded in accuracy by Rowland's Atlas of the solar spec-
trum, and his reproductions of normal lines, published in 1888 and 1893 respectively. His discovery of the concave grating " " method of determining the coincidence in 1891, and hisrelative position of lines, has greatly aided spectroscopic work, since it admits of the production of photographs without the
use of a lens, thus insuring a high degree of comparativeaccuracy. For a considerable time the measurement of the spectra of terrestrial substances did not keep pace with that of thesolar spectrum; KirchhofT's
and Huggins' determinations were
7 duly superseded by the more accurate ones of Thalen, but these were confined to the visible spectrum. Apart from
W. A.
Miller's9
8
incomplete work on the ultra-violetfirst
in 1862,
Lockyer1
in
1881 was the
to accurately investigate the22.
2 3
Partie ultraviolette (Paris, 1881), p. Spectre normal du soleil. P. M. [5] 21, 394; 22, 149; 26, 505. W. A. Beibl. 4, 375; 5, 507. C. r. 90, 182. P. T. 1880, p. 653.
4
Spectre du.9,
fer.
Acta R. Soc. Sclent. Upsala, (1884)
[3], p.
49.
W. A.
Beibl.5
520.
Publ. d. Astrophys. Obs. zu Potsdam (1886), 5. Photographic Map of the normal Solar Spectrum, Johns Hopkins Univ., Baltimore. Astronomy and Astrophysics (1893), 12, 321. P. M.6
(1894) [5] 36, 49.7
N. A.
8 9
S. U. (1868) [3] 6. P. T. (1862) 152, 861. P. T. (1873) 163, 253, 639; (1874) 164, 479, 805.
P. R. S. 25, 546; 27,
49, 279, 409; 28, 157.
8
SPECTRUM ANALYSIS.it,
subject, but he soon quitted
and1
its fuller
examination was
reserved for Hartley and Adeney, and Liveing and Dewar.' 3 Since 1888 Kayser and Runge have met with great success in their important task of measuring the emission-spectraof terrestrial substances
by Rowland's method.
They com-
order to determine the relationship of the various lines of an element, and also that of the lines ofin
menced the work
different elements.
Attempts had been made
in this direction
shortly after the discovery of spectrum analysis by Kirchhoff and Bunsen; it was at first believed that the relationship of
the lines was similar to the sound-waves of a vibrating string, which consist of a fundamental note and harmonic overtones. This view was shown by Schuster in 1880 to be incorrect, and in 1885 Balmer discovered a formula which accurately These invesreproduces the hydrogen lines in wave-lengths. with the observations of Liveing and tigations, together Dewar 6 on harmonic series of similar lines, are naturally connected with Kayser and Runge's work, which has led to the4
5
discovery of the methodical structure of a series of spectra. 7 Rydberg, working independently of Kayser and Runge, has
obtained similar results.
Investigations of this nature have tended to greatly widen the domain of spectrum analysis.
BIBLIOGRAPHY OF WORKS ON SPECTRUM ANALYSIS.
CAPRON.CAZIN.DlBBLTS.
Photographed Spectra.
1877.
La
spectroscopie.
Paris, 1878.Paris, 1895.
DEMARgAY.
Spectres e"lectriques.Spectraal-Analyse.
De
Rotterdam, 1869.
P. T. 1884, p. 63. P. T. 174. 187.
A. B. A. 1888-1894. B. A. R. 1880.
P. R. S. 34, 119, 123. W. A. Beibl. 6, 934; 7, 849. Runge B. A. R. 1888, 576.
W. A. (1885)25.P. T. (1883) 174, 208.
C.1890).
r.
(1890) 110, 394.
K. Vetenskaps Akad. Handl., 23 (Stockholm,
INTRODUCTORY. HISTORICAL.
9
DIETERICI. Spectralanalyse in Ladenburg's Handworterbuch der Chemie. Breslau, 1892.
DRAPER. Catalogue of Stellar Spectra. Cambridge, 1895. GANGE. Die Spectralanalyse. Leipzig, 1893. DE GRAMONT. Analyse spectrale directe des mineraux.Paris, 1895.
GRANDEAU.Paris,
Instruction1863.
pratique
sur
1'analyse
spectrale.
HlGGS.
Photographic Atlas of the Normal Solar Spectrum,1894.
HUGGINS.
Results of Spectrum Analysis Heavenly Bodies. London, 1870.
applied
to
the
KAYSER.
Lehrbuch der Spectralanalyse. Berlin, 1883. measurements of spectra and a very complete (Containsreview of the literature.)
Spectralanalyse in Winkelmann's Handbuch der Physik Breslau, 1894. (Encyclopadie der Naturw.).
Die Spectralanalyse und ihre Anwendung der Astronomic. Berlin, 1879. V. KOVESLIGETHY. Grundziige einer theoretischen Spectralin
KONKERFUES.
analyse.
Leipzig,' 1890.
KONKOLY. Handb. der Spectroskopiker. Halle a. S., 1890. G. AND H. KRUSS. Colorimetrie und quant. Spectralanalyse. Hamburg and Leipzig, 1891. LECOQ DE BoiSBAUDRAN. Spectres lumineux. Paris, 1874.LlELEGG.
LOCKYER.
Die Spectralanalyse. Weimar, 1867. The Spectroscope and its Use. London, 1874. - Studies in Spectrum Analysis. New York and London. 1878.
LORSCHEID.
Die Spectralanalyse.
Munster, 1875.1888.
MACMUNN.
PROCTOR. ROSCOE. Spectrum Analysis.tains popular lectures
The Spectroscope. London, The Spectroscope. London.
the author and A. Schuster.
Fourth edition, revised by London, 1885. (Con-
on the subject supplemented by
IO
SPECTRUM ANALYSIS.
extracts from the more important original memoirs r and a good bibliography.) SALET. Traite elementaire de spectroscopie, I. Fascicule.Paris,
1888.
Die Spectralanalyse der Gestirne. Leipzig, a comprehensive bibliography.) (Contains 1890. SCHELLEN. Die Spectralanalyse in ihrer Anwendung auf die Stoffe der Erde und die Natur der Himmelskorper.
SCHEINER.
Braunschweig, 1883. C. Lassel, edited by
English translation by
J.
and
W. Huggins.
New
York, 1872.
SECCHI.
Die Sonne, German by Schellen.Spectralanalyse
Braunschweig,
1872.
THALEN.
expose och
Historick,
med
en
Spectralkarta.
TUCKERMAN.VlERORDT.
Upsala, 1866. Index to the Literature of the Spectroscope.
Washington, 1888.
Anwendung
des Spectralapparates zur
Photo-
VOGEL H. W.Berlin,
metric und zur quant. Analyse. Tubingen, 1873. Prakt. Spectralanalyse irdischer Stoffe.1889.
(Deals chiefly with practical analysis,
and particularly with absorption-spectra.) WATTS. Index of Spectra. Manchester, 1889. (Contains complete measurements of spectra and a very full
Supplements to the index appeared in bibliography. the B. A. R., London.) YOUNG. The Sun. New York and London, 1897.Seealso
text-booksd.
on
physics,
amongst
others:
A.
Lommel, Lehrb.Miiller-Pouillet's
Experimentalphysik (Leipzig-, 1893); Lehrb. d. Physik, 9. Aufl. v. Pfaundler1894);
(Braunschweig,
(Breslau, 1893); Kelvin
&
Winkelmann, Handb. d. Physik Tait, Elements of Natural Philos-
ophy; Tait, Light; Tyndall,
On
Light; Wright, Light.
CHAPTER
II.
PHYSICAL PROPERTIES OF LIGHT.
1
light consists of
Huygens' universally accepted theory, wave-motions of the ether, the vibrations being transmitted from particle to particle with an extremely
ACCORDING
to
high velocity in straight lines; the vibrations of the particles On of ether are at right angles to the path of the ray. of the ether, and the ease with account of the great elasticity
which the vibrations are further propagated, single rays cannot be obtained, but only pencils consisting of a number of rays, which may be considered to be parallel if it is assumed that the vibrations are very small, or at a great distance from
The varying frequency of the vibrations produces the eye the effect of color; the number of vibrations is constant for each color, but in a given medium the waveSince all light-rays are transmitted with a length differs.the source.in
uniform velocityso inair,
in
the
number
the free ether or in a vacuum, and almost of vibrations is small or great in propor-
waves are long or short. Wave-length. It is possible to directly determine the wave-length corresponding with a given color in air, and it istion as the
found that(A) of the
at the
=1
A-Yme = 0.00076 mm., 0.000589 mm., and that of the
extremity of the visible red the wave-lengththat of the yellow Z?,-line^f-lirie
at the limit of theis
visible violet
=
0.00039
mm
-
The
velocity (v) of light4, 87,
Comp. Fehling-Hell's Handworterbuch,
and text-books
of
Phy-
sics.ri
12
SPECTRUM ANALYSIS.to be about 300,000 kilometres per second; the(n)is
known
num.
ber of vibrationsIn this mannerit
is
obtained by the expression n == A
found that the number of vibrations of
= 395, 509, and 763 billions per second These numbers are inconceivably great, and respectively. awkward to write, and it is therefore usual to define the color by the wave-length, although this varies with the medium. In dealing with wave-lengths measured in a vacuum, thethe above three linesmillionth part of a millimetre
=
o.ooi mikron
is
taken as theit is
unit, and, in accordance with Kayser's suggestion, sented by the symbol /i/ 3 -line of
lend
confirmation
cleveite,
helium; but atmospheric argon contains at least three bright lines in the violet which are not shown by the gas fromcleveite;
hence Ramsay concludes that atmospheric argon is Berthelot obtained a fluorescent specprobably a mixture.1
trum by the action of a moderately strong induction-current on a mixture of argon, benzene vapor, and mercury in a Geissler tube; the spectrum differs from that given by any other gas, and the yellow and green rays were perfectlyvisible in the spectroscope infull daylight. He considers that the spectrum is that of a compound of argon and mercury with the constituents of benzene, but Dorn and Erdmann 2
found
that
nitrogen.
spectrum between A = 5060 and 3320/1/1, using a powerful concave grating, and Kayser has published a preliminary list of the lines in the blue spectrum, the gas being obtained from4
some of the lines were those of mercury and Eder and Valenta have photographed the argon3
the atmosphere; the lines observed are not given in Rowland's
Atlas and reproductions of the Fraunhofer1
lines.
C.
r.
(1895) 120, 062, 797, 1049. 1386; (1897) 124, 113.
7 1
Ann. (1895) 287, 230. Wiener Akadem. AnzeigerLieb.
(1895),
No.d.
21.
C. N. (1895) 72, 99. Newall, C. N. 71, 115.
4
Sitzungsber.
Berl.
Akad.
(1896) 24.
See also
IOO
SPECTRUM ANALYSIS.Trowbridge and Richards1
find that the oscillatory dis-
is an important factor in producing charge of the condenser The pure red spectrum is of argon. the blue spectrum of an obtained if the tube is connected with the terminals
electric
machine; but if the spark-gap trum changes at once to blue.
is
interposed, the spec-
Red spectrum7723-
V
SPECTRA OF THE ELEMENTS.3376.61
1OI
102
SPECl^RUM ANALYSIS.Arc and spark spectra:6170.7*4467.0!3825.1!2991.11
6111.2*4459-4t3785-of
5652.1*
5559-2*4036.7!
5499-1*3949- 2 t
5332-1*3931-4! 3053.o!
4494-7t3922. 3t
443 I -7t
3119692860.542492.98
3075.442830.2!2456.61
3057-7t
3032-962601.2!2370.85 2157.1!
2898.832526.4!
2780.302437.302228.77 2067.26
2745.092381.28
2528.3!
2369.752148.2!
2349922r.i4.2i
2288.192133.92
2271.46
2165.642009.31
2113.14
BARIUM.barium has been investigated by 4 Kirchhoff, Huggins, Thalen, and Lecoq de Boisbaudran; the arc-spectrum by Lockyer, Liveing and Dewar/ and, most accurately, by Kayser and Runge, who employed theof1
The spark-spectrum2
3
6
7
chloride and carbonate,
and measured
162 lines.
Barium
compounds are gradually dissociated in a hot Bunsen flame, and all exhibit the band-spectrum of the oxide, together withlineA,
=
5
535. 69 of the metal.
Immediately on their introduc-
produce their own peculiar fugitive these can always be obtained with certainty if a wire spectra; holding ammonium chloride is placed in the flame below thetion the haloi'd derivativessalt under examination. For prolonged experiments hydrogen chloride, hydrogen bromide, or iodine vapor must be introduced into the flame. The flame-spectra
specimen of barium
of these
compounds have been studied by Mitscherlich
8
and
Lecoq de Boisbaudran.1
A. B. A. 1861.P. T. (1864) 154, 139.
a
3
N. A.
S.
U. (1868)
[3] 6.
46 *'
Spectres lumineux (Paris, 1874). P. T. 163, 369; 164. 806.Ibid. (1883)
8
174, 216. A. B. A. 1891. P. A. (1862) 116, 419;
(1863) 121, 459.P. A. 110, 161.
also
Bunsen and Kirchhoff, Only Only
For the flame-spectrum see Bunsen, P. A. (1875) 155, 366.
*!
visible in the spark-spectrum.
visible in the spark-spectrum.
(Thalen.) (Hartley and Adeney.)
SPECTRA OF THE ELEMENTS.Arc and spark spectra:6497 07
IO3
104
SPECTRUM ANALYSIS.BISMUTH.
spark spectrum is obtained by the use of bismuth 2 electrodes, and has been measured by Huggins, Thalen, and1
The
the arc-spectrum by Liveing and and recently, commencing at 6i8/f/w, by Kayser and Dewar, The spark-spectrum exhibits many lines that are Runge. Bismuth salts, moistened with absent from that of the arc. hydrochloric acid, produce in the Bunsen flame a fugitive
Hartley and Adeney;4
3
6
band-spectrum of the oxide. The spectra of the compounds themselves are obtained by volatilizing them in a hydrogen 6 flame. They have been drawn by Mitscherlich.
Arc and spark spectra:6493.8*
^
SPECTRA OF THE ELEMENTS.!
105
third,
have also been observed by Hartley in the sparkfound, however, fourteen spectrum; Eder and Valenta2
additional lines, the majority of which are double, and confirmed the presence of four that had been detected by
have recently photothe arc-spectrum between A 2 100-4400. graphed Onl)' the double line could be detected; the numerous bands areCiamician.
3
Rowland and Tatnall
4
=
probably due to some compound, such as boric anhydride. Boric acid and its salts produce a characteristic band spectrumin the
Bunsen flame. Arc and spark spectra:3450.8*(2497.8212496.867)5
2267.0!
2266. 4f
BORIC ACID.
The wave-lengthFlame-spectrum63985193:
is
measured6032 4722
at the
middle of the bands.
6211
5808
5481
5440
4912
4530
BROMINE. Bromine vapor gives a line-spectrum with the electric spark, but the measurements of it are only approximate.6
Its
absorption-spectrum at the ordinary temperature has been7
accurately investigated by Hasselberg;1
when
a high disper-
P. R. S. 35, 301.
2 3
Denkschr.Sitzber. d.
d. Wien. Akad. (1893) 60, 307. Akad. d. Wiss. zu Wien. [2] 82,r.
425.
See also Troost and
Hautefeuille, C.45
(1871) 73, 620.
Salet, A.
c. p.
(1873) [4] 28, 59.
Astrophys. Jour. (1895) 1, 16. Lecoq de Boisbaudran, Speqtres lumineux (Paris, 1874). Thalen, Upsal. Universit. Arsskrift. 1866. Also Salet and Eder, and Valenta, as above. 6 A. c. p. [4] 28, 26. Plucker, P. A. Salet, Spectroscopie (Paris, 1888). Plucker and Hittorf. P. T. 155, i. Ciamician, Wien. 105, 527; 107, 87.Ber. 767
[2],
499;
77
[2],
839;
78
[2], 867.
K. Svensk. Akad. Handlingar. (1891) 24, No. 3. Mem. de 1'acad. de St. Petersb. (1878) 26, No. 4. See also Daniell and Miller, P. A. 28, 386. Roscoe and Thorpe, P. T. 167, 209. Moser, P. A. 160, 188.* Visible only in the spark-spectrum. f Visible only in the spark-spectrum.
(Hartley.)
(Eder and Valenta.)
io6sionfine
SPECTRUM ANALYSIS.employed lines groupedisit
seen to consist of a large into bands.is
number
of
The spectrum obtained with a continuous discharge differs from that produced when a condenser is included in thecircuit.1
Spark-spectrum of bromine vapor:7000*6148
6780*5876(5450
6630*58305423)
65835723(5327
65595595305
6546(5509
63535497
54905166)
5240
5184
5060
49303980:
(4816
4788)
4705
4677
4618
4366
Absorption-spectrum
SPECTRA OF THE ELEMENTS.Group
lO/
108chloride,
SPECTRUM ANALYSTS.
90 Cadwhich have been measured by Hartley and Adeney. mium chloride and bromide are dissociated in the Bunsen flame, and exhibit the lines X = 5086, 4800, and 4678,1
but usually the metal. The arc-spectrum differs latter exhibits a pair considerably from that of the spark; the 5378.8 and 533$. 3> of lines of the highest intensity of \ absent from the former, and the same applies to which are 4215 and 2111 lines of inferior brightness between A
=
Arc and spark spectra:6467.3*4678. 37f
6438.8*4662.69 3261.172639.632239.93
5378.8*4413.23(3252.63
5338.3*3613 043133.292573.122144.45
5154-85 3610.663081.03)
5086.06f3467.762980.75 2312.95
4800.09f 3466.332880.88
3403.742763.992267.53
2601.992194.67
2329.35
2288 10
CESIUM.,
2
Bunsen and KirchhofT discovered caesiumof
in
1861
by
means
spectrum analysis.
Its salts are all dissociated in
the Bunsen flame, and exhibit the lines of the metal; the more prominent ones are X 4555 and 4593 in the blue, andA.
=
6010 in the orange. Arc, spark, and flame spectra:6973.96723.6
6213.43888.83
6010.63876.73
5845.1
5664.0
5635.1
4593-341
4555-44
3617-08
3611.84
hoff,
P. T. (1883) 175, 98. See also Thalen, N. A. S. U. (1868) [3] 6. KirchA. B. A. 1861. Mascart, Annales de 1'Ecole normale (1866), 15.
Lockyer, P. T. (1873) 163, 369. Cornu. Journ. de Phys. (1881) 10, 425. Liveing and Dewar, P. R. S. (1879) 29, 482. P, T. (1888) 179, 231. Ames, P. M. (1890) [5] 30, 33. Bell, Am. Journal oi Sciences, June, 1886. 2 Kayser and Runge, A. B. A. 1890. Bunsen, P. A. 119, i; 155, 366. Johnson and Allen, P. M. [4] 25, 199. Thalen, N. A. S. U. (1868) [3] 6. Lecoq de Boisbaudran, Spectres lumineux (Paris, 1874). Lockyer, P. R. S.(1878) 27, 280.
Liveing and Dewar,
Ibid. (1879) 28, 352.
*
Only
visible in the spark spectrum.
(Thalen.)
f Visible
also in
the flame
spectrum of the chloride and bromide.
(Lecoq de Boisbaudran.)
SPEC7^RA OF
'1
HE ELEMENTS.
109
CALCIUM.been measured by 4 Lecoq de Boisbaudran, Huggins/ 6 5 Lockyer, Cornu, Liveing and Dewar, and more recently by who employed the electric arc and Kayser and Runge, The faint bands which occasionally appear calcium chloride. in the yellow and red when the arc is used are considered byline-spectrum1
The
of
calcium3
has7
Kirchhoff,
Thalen,
8
be due to oxide. Many of the and are therefore always calcium produced, H. BecquereP visible when carbon electrodes are employed. observed bands from A = 8880-8830 and from A = 8760-8580 The haloid compounds have been investiin the infra-red. 10 gated by Bunsen, Mitscherlich, and Lecoq de Boisbaudran; in the Bunsen flame some bands peculiar to each compound are visible, together with those of the oxide and the blue The oxide bands are also line, A 4226.91, of the metal.
Lecoq de Boisbaudran
to
lines are readily
11
=
produced
if
the flame
is
charged with hydrogen chloride,fluoride.
hydrogen bromide, hydrogen iodide, or hydrogen Arc and spark spectra:6499.85
I I
O4355-
SPECTR UM ANAL YSIS.
SPECTRA OF THE ELEMENTS.investigated by
Ill
Swan from 1850 onwards.2
'
In3
common
with4
Angstrom, Thalen, and Liveing and Dewar, he ascribed it to hydrocarbons, but the last workers, together with Attfield,5
Morren,
and Dibbits,
8
due
to carbon, since
it is
subsequently recognized that it was produced by the combustion of pure
cyanogen in dry oxygen. This band-spectrum consists of five complex bands, with the following wave-lengths according to Angstiom and Thalen, and Watts:7
i
or orange band.'
y^jlow^band
3
or & reen band
-
4
or blue band.
5
or indigo
band
6187-5954
5633-5425
5164-5032
4736-4677
4381-4232
three medial bands have been recently measured by and the green one by Kayser and Runge; 9 for the Fievez, o8
The
others there are only the old observations of Watts, Angstrom 10 available. In addition to and Thalen, and Piazzi- Smyth the above bands others are sometimes observed in the arc; they occur in the blue, violet, and ultra-violet, and have thefollowing wave-lengths:I
Band.
II
Band.
Ill
Band.
IV Band.
V
Band.
4600-4500
4290-4150
3884-3850
3590-3550
3370-3350
in the arc is doubted by Kayser and and Dewar have ascribed them to cyanogen, Runge; Liveing H. W. Vogel, and others regard them as a whilst Lockyer,
Their existence11
1
P. T. E. (1857) 21, 411.
2
N. A. S. U. (1875)
9.
3
P. R. S. (1880) 30, 152, 494; (1882) 33, 403; (1883) 34, 123.Ibid. (1862) 152, 221.
P. T. (1882)
174, 187.P.
M.
(1875) 49, 106.
A.
c. p.
(1865) [4] 4, 305.
P. A. (1864) 122, 497. P. M. (1869) [4] 38, 249; 45, 12; (1874) 48, 369, 456; (1875) 49, 104.
Mem. de 1'Acad. roy. de Belgique (1885), 47. A. B. A. 1889. P. M. (1875) [4] 49, 24; (1879) [5] 8, Astr. Obs. Edinb. (1871) 13, 58. P. T. E. 30, 93. 107. 11 P. R. S. (1878) 28, 308; (1880) 30, 335. See also Plucker, P. A. (1858) 105, 77; (1859) 107, 533, and with Hittorf, P. T. 155, i. Jahresber. (1864) Van der Willigen, P. A. (1859) 107, 473. Huggins, P. T. (1868) p. no.IJ
1 1
2
SPE C TRUM A NA L YSIS.
second band-spectrum of carbon produced only at high tembut experiments Kayser at first shared this view, peratures.
made
A
a different conclusion. conjunction with Runge led to was directed on to the strong current of carbon dioxidein
arc,
appeared.
fainter and diswhereupon the cyanogen bands became that this was not due to a In order to prove
current of air was lowering of the temperature a still stronger substituted for the carbon dioxide: the bands immediately increased in brightness in consequence of the additional The view that the cyanogen bands are supply of nitrogen. their occurrence in essentially due to carbon is supported by last fact was long comets, and in the solar spectrum; this That the specdoubted, but was established by Rowland.
trum
of a
compound which
is
dissociated at 1000
visible in
the solar spectrum appears
should be somewhat paradoxical,
but Kayser and Runge have pointed out that the carbon molecule, as is shown by its varying specific heat, is not a constant quantity, and the "cyanogen bands" maybe the spectrum of an unknown compound of carbon and nitrogen
which
is
capable of
existence at very high temperatures.
The cyanogen bands have been measured by Liveing andDewar, and the and Runge.third, fourth,
and
fifth
ones also by Kayser
The carbon bands all have their brighter edges directed towards the red end of the spectrum; each possesses a number of edges, varying from three to seven, which become weakertowards the violet. The lines extend from the first edge of one band to the beginning of the next, so that no portion of the spectrum from 620^ to 340^ is free from carbon lines, the total number of which is at least 10,000. Metallic spectraobtained by means of the arc and carbon poles always exhibit158, 558.r.
(1871) 73, 620.
Lielegg, Wien. Ber. (1868) 52, 593. Troost and Hautefeuille, C. Wullner, P. A. (1872) 144, 481. Salet, A. c. p. (1873) [4]
28, 60.
Lecoq de Boisbaudran, Spectres lumineux (Paris, 1874). Wesendonck, Inaug-Diss. (Berlin, 1881). Hartley, B. A. R. 1883. Eder, Denkschr.
Wiener Akad.
(1890) 57.
SPECTRA OF THE ELEMENTS.
11$
the metallic lines superposed by the carbon bands, hence a
good knowledge6584.0
of the latter
is
very desirable.
Line-spectrum:6578.53920.02478.35695.1
5661.9
4266.62509.0
2837.22296.5
2836.3
Band-spectrum:I.
II.
Orange Band 6187 Green-yellow Band:i.
5954:
6188. 2
6119.95633-4
Edge:
5635.3
5634-3
5633-9
1144728.42.
SPECTRUM ANALYSIS,
Edge:
3-
Edge:
4.
Edge:
SPECTRA OF THE ELEMENTS.
1*5
SPECTRUM ANALYSIS.
IV.
SPECTRA OF THE ELEMENTS.'
\\'J
observed that the chlorine-spectrum is produced by passing powerful sparks through glass tubes containing The spectrum chlorine compounds under low pressure.
berg
obtained with a powerful continuous current differs from that 8 produced when a condenser is introduced into the circuit.
There are no recent measurements of the absorptionspectrum of chlorine. Spark-spectrum:
5457.8
5444-7
5425.0(4905.4
5393-44897.8)3
(5220.8
52172)4810.7
5103.2
5099.0
5078.4
4918.1
4820.8
4794.9
Absorption-spectrum:
Numerous absorption-bandsin the violet.
in the
green and blue, total extinction
CHROMIUM.of chromium between D and A = 3430 measured by Hasselberg. Huggins and has been accurately Thalen had previously investigated lines of the spark-spec-
The arc-spectrum6
4
5
trumlines
in
the visible region, LockyerA.
between worked on thetions of1
=
observed some additional and 3900, and Liveing and Dewar 8 4000Solucharacteristic absorp-
7
ultra-violet portion of the arc-spectrum.
chromium compounds produceAcad.St.
Bull.
Petersb. 28, 405.r.
106, 624.
Ditte, C.
73, 622.
Pliicker,
See also Van der Willigen, P. A. P. A. 107, 528. Pliicker and
Hittorf, P. T. 155, i. Angstrom. C. r. 73, 369. Thalen, K. Svenska Vetensk. Akad. Handl. 12, No. 4, p. 8. Salet, A. c. p. [4] 28, 24. Ciamician, Wien. Ber. 78, 872.2
Trowbridge and Richards, Amer. Jour.
Sci.
(1897) [4] 3, 117.
P.
M.
43, 135-
Morren, P. A. (1869) 137, 165. Sillim. Journ. [2] 47, 417. Svensk. Vetensk. Akad. Handl. (1894) 28, N. 5P. T. (1864) 154, 139.
N. A.
S.
U. [3]
6.
P. T. 1881.
P. R. S. (1881) 32, 402. See also
1878, p. 413.
Ber. 8, 1533.
ches sur
le
spectre solaire.
H. W. Vogel, Monatsber. Berl. Akad. Kirchhoff, A. B. A. 1861. Angstrom, Recher1868. Lecoq de Boisbaudran, Spectres lumi-
neux
(Paris, 1874).
1
101
SPECTRUM ANALYSIS.
tion-spectra that have been frequently studied; the more The spectroimportant are shown in Fig. 41, Chapter VIII. scopic
determination
of
potassium
chromate,
potassium
bichromate, and chrome alum is described in G. and H. Kruss* work on Colorimetry and Quantitative Spectrum Analysis.
Arc-spectrum5791-20
:
SPECTRA OF THE ELEMENTS.that of the arc; Lockyer portions of the spectrum.l
119
have also investigated has recently measured and A = 3450, and the lines of the arc-spectrum between 4 and Dewar, those of the arc and spark spectra in the Liveing8
and Cornu
*
Hasselberg
D
ultra-violet region.
The
lines of the
two spectra
differ
not
number, but also in intensity. The absorption-spectra of cobalt glass, and of solutions of cobalt compounds are very & characteristic; they have been examined by H. W. Vogel, Russell, Russell and Orsman, and by C. H. Wolff, and are shown in Fig. 41, Chapter VIII. The following test is stated by Wolff to be one of the most delicate known in chemistry: Ammonium thiocyanate is mixed with cobalt chloride solution, and shaken with amyl alcohol and ether; this dissolves the cobalt thiocyanate, and the solution gives a characteristic absorption-spectrum. The method was used for the spectroonlyin6 7 8
colorimetric determination of cobalt
when presentof cobaltJ.
in
smallin
quantity.
The absorption-spectrumis
chloride
hydrochloric acid solutionparticularly sharp, butif
statedis
by W.
Russell to be
the acid
concentrated the broad
bands usually observed are resolved into smaller ones, almost coincident with those produced by ferric chloride under the
same conditions.
He
believes that the solvent causes a dis-
sociation of the dissolved substance.
Arc and spark spectra:6143.8*5483.571
6122.3*5477.13
5531-06
5525-275444-81
5523-565407-75
5489.905381.99
5484.22
5454-793.
5369.79
P. T. 1881.
Part
2
3
Spectre normal du soleil (Paris, 1881). Svenska, Vetensk. Akad. Forhandl. (1896) 28, No.
6.
From D
A 3450.
Astrophys. Jour. (1896) 3, 288; 4, 343; (1897) 5, 38. 4 From A. 3450-2244. P. T. (1888) 179, 231. 5 Ber. 11, 916. Monatsber. Berl. Akad. 1878, p. 415.67
J.8
Ber. 14, 503. Ber. 24, 619. See also Etard, C, Zeitschr. Anal. Chem. 18, 38.P. R. S. 31, 51.
Chem.
Soc. 1889, p. 14.
r.
(1895) 120, 1057.
* Visible only in the spark-spectrum.
I2O5362.97
SPECTRUM ANALYSIS.
SPECTRA OF THE ELEMENTS.
121
COPPER.
The spark-spectrum of copper, in the visible field, has been 2 measured by Kirchhoff, and Thalen, and, as far as wavelength 4275, by Lecoq de Boisbaudran; in the ultra-violet 4 Hartley and Adeney have measured the portion between that A 3999 and 2103, and Trowbridge and Sabine between A = 2369 and 1944. Liveing and Dewar" have 2294-2135, whilst, photographed the arc-spectrum from A1
3
&
Kayser and Runge have done the same for the between A. = 6000 and 1944; they measured 304 lines, region and obtained the spectrum by substituting, for the carbon poles, rods of copper 1-2 sq. cm. in section.
more
7
recently,
on one
Scarcely any of the copper lines are sharply defined even side, so that the spectrum has a peculiar appearance. In the Bunsen flame cupric chloride produces a band-spectrumfield,is
extending over the wholeviolet;
the same spectrum
with the exception of the obtained with the metal if the
The absorption-spectra of flame contains hydrogen chloride. salts are not characteristic, as the compounds produce coppertotal extinction both in the red
and the
violet.
Ewan found
B
that, in aqueous solution, the spectra of the chloride, sulphate, and nitrate change with progressive dilution tending to become identical; this observation is in agreement with the
C. H. Wolff has sugtheory of electrolytic dissociation. gested a spectro-colorimetric method for the determination of
9
A. B. A. 1861. N. A. S. U. (1868)
6.
Spectres lumineux (Paris, 1874). P. T. (1883) 175, 63. Proc. Amer. Academy, 1888. P. M.P. R. S. (1879) 24, 402.
[5] 26, 342. P. T. (1883) 174, 205.
A. B. A. 1892.89
P.
M.
1892, p. 317-
Ber. 25, 495c.18, 38.
P. R. S. (1895) 57, 128.
Zeitschr. anal.
Chem.
122
SPECTRUM ANAL YSIS.'
copper
in small quantity,
and P. Sabatier
has studied the
of cupric bromide. absorption-spectra of solutions
Arc and spark spectra:5782.30
4704.77 4480.593602.1 1
3247.65
2618.462303.18
2199.77
SPECTRA OF THE ELEMENTS.
123
substances have not been sufficiently studied to render their Kriiss recognition as elements absolutely free from doubt.
and Nilson, as thetion-spectra,
result of their investigation of the absorp-
that didymium, erbium, holmium, and thulium are composed of more than twenty samarium, elements; their conclusion is based on the assumption that each element has a characteristic maximum of absorption, butcious.
consider
Schottlander's extensive investigations show that this is fallaBailey has also raised objections to Kruss and Nil-
son's conclusions.
At
present the results of the spectroscopic
work on the rare earths is so uncertain, that the data given in " " this book usually refer to the old elements. Bahr and Bunsen found that didymium oxide, like erbium oxide, when heated in the Bunsen flame gives a continuous spectrum, andalso
characteristic bright lines
which are almost coincident
with the absorption-lines exhibited by solutions of the salts, or by glass which contains the metal; this is no exception to the rule that solids only yield continuous spectra, for Huggins
and Reynolds showed that the earths are volatile
in
the oxy-
hydrogen
flame.
didymium
Comparison of the absorption-spectra of chloride, sulphate, and acetate led Bunsen to the
conclusion that the bands tend to approach the red as the molecular weight increases. The absorption-spectra of therare earths in the ultraviolet has been investigated
by Soret.
Spark-spectrum:5486.0*5192.5
5372.05191. 5
5361.55130-341.09.8
5319-9
5293-5
5273-5
5249.5
4924.5 4060.7
4463.2
4452.3
4446.7
4328.1
4303.6
*
Due
possibly to samarium.
124
SPECTRUM ANALYSIS.DIDYMIUM CHLORIDE.Absorption-spectrum:'
b (7431.7* 5 886f5206)
7361.7* 5824*(5125.8*
7308.7*)
6895.6*
6793.3*5720)
[>]b(5963t[/?]
5789*5088*)
5748*4823!
b (5313*
4759
4692!
4441.7
'OLD" DIDYMIUM NITRATE. Absorption-spectrum: positions of minimum4
of brightness:575946335317
72915253
6906 52174289.6
679451474173-6
64075126
6235
61894771
57974695
4826
4443
4341
PRASEODYMIUM NITRATE.729167945916
5797
5759
531?
52172
5125
4826
4695
4443
ERBIUM.
The remarks on didymium applySpark-spectrum58274899.9:
also to this element.
i
5763487.2.4
5344-4
52574674-9
52i84606.3
51894501.3
4952
4820
Lecoq de Boisbaudran, Spectres lumineux (Paris, 1874). C. r. (1887) Bunsen, P. A. 155, 366. Ann. Chem. Pharm. 128, 100; 131, 255. Huggins and Reynolds, P. R. S. 18, 546. Lippich, Sillim. Journ. (1873) [3] 13, 304. Auer v. Welsbach, Sitzungsber. Wien. Akad. (1885) 92. Crookes, C. N. 54, 27. Schuster and Bailey, B. A. R. 1883. H. Becquerel, C. r. 104, 777, 1691; 106, 106. Haitinger, Monatsch. f. Chem. (1891) 12, Kruss and Nilson, Ber. 20, Soret, C. r. 86, 1062; 88, 422; 91, 378. 362.1
105, 276.
2143.569.2
Bailey, Ber. (1887) 20, 2769, 3325.
Schottlander,
Ber. (1892) 25,
Spectra Yttrium, Erbium, Didym och Lanthan (StockBunsen Ofversigt K. Vetensk. Akad. Fdrhandl. (1881) 40. and Bahr, Ann. Chem. Pharm. 137, i. Huggins, P. R. S. 1870. Bunsen, P. A. 155, 366.
Thalen, holm, 1874).
Om
*f
Neodymium.Praseodymium.
SPECTRA OF THE ELEMENTS.ERBIUM CHLORIDE.Absorption-spectrum6839 53646671[a] 5232:
12$
1
6535
6405 4875
5410
4922
4516
FLUORINE.no accurate measurements of the spectrum of fluorine. By the passage of induction-sparks through silicon a obtained a beautiful blue band-spectrum of fluoride Salet the compound; the incission of a Leyden jar produced the
There
are
spark-spectrum of fluorine.3
Commencing
at Salet's last lines
Liveing
measured the flame-spectrum. Spark-spectrum:
6922*
6862*:
6782*
6401
6231
Flame-spectrum6231
6091
6011
5571
5321
GALLIUM.
Lecoq de Boisbaudran, who discovered this element, measured its spark-spectrum, and Liveing and Dewar that of5
4
the arc.
Spark and arc spectra:41714031
GERMANIUM.of germanium has been investigated and by Lecoq de Boisbaudran, who calculated its by Kobb,8 7
The spark-spectrum
Lecoq de Boisbaudran, Spectres lumineux (Paris, 1874). Bunsen, P. A. 155, 366. Bunsen and Bahr, Ann. Chem. Pharm. 137, i. 2 A. c. p. (1873) 28, 34. 3 Proc. Cambridge Phil. Soc. 3, Pt. 3. See also Mitscherlich, P. A. 121,1
476.46 61
Seguin, C.C.r.
r.
(1862) 54, 933.
82, 168.
P. R. S. 28, 482.
W.C.
A. (1886) 29, 670.r.
(1886) 102, 1291.
Ber.
l,
479.
*
Only approximate.
126
SPECTRUM ANALYSIS.*
atomic weight from his measurements. Rowland and Tatnall have recently photographed the arc-spectrum between A =
2300-4600. Arc and spark spectra:63375131
6021 4814
58934743
5256.5
5229.5
52104261
5178.5
5135
4685.3
4291-6
4226
41792709.734*
3269.628*
3124.945*
3039.198*2651. 219f)
2754.698*
2740.535* 2417.450*
2691.446* (2651.709*
2592.636*
GOLD.Liveing and Dewar measured three lines in the ultra-violet exhibited by the arc-spectrum, and these were the only ones*
known when Kayser and Runge commencedtion of the region
3
their investiga-
between wave-length 6600 and 2280. They
usually employed fine gold, but occasionally auric chloride and carbon poles. The visible portion of the spark-spectrum
has been measured by KirchhorT, Huggins, Thalen, 6 and G. Kriiss, who ascribes the line 5230.47 to platinum, and not7
4
5
to gold.
Arc and spark spectra:6278.374488.46 2676.055957-245837-64 3122.88
5656.00 3033-38
5230.47
5064.75
4792.792905.98
4065.22 2428.06
3029.32
2932.33
HELIUM.
The yellow /Vline
of the solar
until recently, to a hypothetical element,Astrophys. Jour. (1895) P. T. (1882) 174, 2219. A. B. A. 1892.Ibid.1
spectrum was ascribed, termed by Frank-
1, 149.
86 1.
P. T. 1864, p. 139.
N. A.Lieb.
S.
U.
[3]
6.
Ann.
(1887) 238, 30.1874).
See also Lecoq de Boisbaudran, Spectres
lumineux (Paris,*f
Arc-spectrum.Possibly a single reversed line.
SPECTRA OF THE ELEMENTS.1
I2/
land helium; this was isolated by Ramsay in 1895 from cleveite, in which it occurs together with argon; he also obtained it from certain meteorites from Augusta Co.,Virginia.
Clevein
2
showed thatin its
it
is
present,in
by argon,to D^.
cleveite
from Carlshuus
unaccompanied Norway, and he
observed the presence3
spectrum of
five lines in addition
Deslandres, the following lines:66784437.9 3819.7
using a very high dispersion, measured
5876.04388.43705.4
5048.4
5016.0
4922.24026.23187-9
4713.35
4143-93613-84
4120.93447-7
3964.02945.7
4471.75 3888.75
Runge and Paschen, in the course of an investigation of the gases from cleveite, showed that the line at 5876.0 is a double one, and, as the solar helium line had always been regarded as single, doubt was cast on the identity of solarThis point was speedily settled by and Hale, who showed that the solar Z> -line is also Huggins double. Kayser found that a Geissler tube containing what he supposed to be the purest atmospheric argon also showed
and
terrestrial helium.5
8
6
the Z> 3 -line, thus affording proof that helium7
is
present in the
helium lines many Lockyer atmosphere. coincide with some of hitherto unknown origin in the spectra of the chromosphere, and of the white stars of Orion. Understates that
of the
the influence of the silent discharge helium combines with mercury and benzene or carbon bisulphide to form a com-
pound resembling that mercury alone.1
of argon, but
it
does not combine with
C.
r.
120, 660, 1049. 120, 834.
Ber. 28, 318, 448.
N. 52, 224.
Ramsay,
Collie,
and Travers, Jour. Chem. Socy.2
(1895) 67, 648.
C. C.
r.r.
Ber. 28, 373.
3
45 61
W.
(1895) 120, nio, 1331. A. Beibl. 19, 634.
C. N. 72, 26.Ibid. 72, 99.
See also Brauner, C. N. 71, 271. P. R. S. 58, 67. C. r. 120, 1103. Palmieri, Acad. di Napoli Rendic. (1882) 20, 233.
128
SPECTRUM ANALYSIS.Berthelot*
and Runge and Paschen
a
have observed that
the spectrum of cleveite gas consists of six series, two pairs of which are characterized as subseries, whilst two series are
Two spectra are thus differentiated which principal series. are ascribed to two constituents of the gas, and which bear a 3 Rydberg striking similarity to the spectra of the alkalies.has confirmed these conclusions, and termed the second constituent parhelium.thisin the separation of
Some
confirmation was also afforded
to-
view by Ramsay and Collie's researches, which resulted helium into a lighter and a heavier por-
tion; but
Ames
difference in
were unable to detect any and Humphreys their spectra, although they used a spectroscope
4
of high dispersive power. When further separated the heavier portion was found to consist chiefly of argon.
HYDROGEN.
Two spectra, termed the elementary and compound linespectra, are exhibited by hydrogen in a Geissler tube; theirproduction depends on the conditions of temperature and The former has been measured by Angstrom, 5 pressure.
H.
W.
8
7
Vogel,first
latter
was
Huggins, Cornu and Ames; the 10 but was investigated by Plucker and Hittorf,Lockyer,9
8
11 ascribed to acetylene by Angstrom, Berthelot and Richard, 12 and Salet. The incorrectness of this view was
proved by
(1897) 124, 3 2 Sitzber. Berl. Akad. (1895) 639, 759. Astrophys. Jour. (1896) 3, 4..
1
C.
r.
n
W. A.
Beibl. (1895) 19, 884, 885.
3
W. A.
(1896) 58, 674. Astrophys. Jour. (1896) 4, Astrophys. Jour. (1897) 5, 97. P. A. (1864) 91, I4I; 123, 489; (1872) 144. 300. Berl. Monatsber. (1879) 586; (1880) 190. Ber.P. R. S. 28, 157 P. T. 171, 669. P. M. (1890)[5]1011;
91.
(1880) 13, 274.
30, 31.
30, 33.
P. T. (1865) 155, 21. C. R. 68, 810. 1035,
Plucker, P. A. 107, 4Q 7.1107, 1546.
12
A.
c.
p. [4]
28,
17.
SPECTRA OF'
J^HE
ELEMENTS.
129
In the spectrum of exact measurements. Hasselberg's 2 in addition to dark hydrogen C Puppis Pickering found, lines and K, two broad lines at A 4633 and A 4688, and
=
a peculiar series of dark lines whose wave-lengths are rhythmiThese were A 4544, 4201, 4027, 3925, 3859, cally related. It was first thought that they represented some 3816, 3783.
new element not yet found on
the earth or in the stars, but
they are very probably due to hydrogen, produced under conditions of luminosity hitherto unknown. By applying
Balmer's formula, Pickering found that the new lines form a 3 harmonic series. This conclusion was confirmed by Kayser, who pointed out that hydrogen had been the only element,
having harmonically related
lines,
which had possessed only
a single series of such lines. Kayser and Runge had previously found that two of the series of lines of an element endat
nearly
the
same
place.lines,
On examining
the oscillation
frequencies of thethis characteristic,
new
Kayser concluded that they have
and constitute a new hydrogen series. If in laboratory experiments, imthese lines can be produced portant information as to stellar temperatures and pressures is likely to be obtained. At low temperatures ivater vapor gives an absorptionspectrum rich in lines which are chiefly confined to the redthese constitute a large number of the terrestrial lines, and are referred to under nitrogen they are strongest when the sun is low in the horizon, as its raysregion;
Fraunhofer
;
have then to traverse a considerable layer of the atmosphere. " " When the latter is saturated withmoisture, a
rain-band
is
visible with the1
help of a spectroscope of
low dispersive
Bull. Acad. St. Petersb. (1880) 11, 307;
St. Petersb. (1882)
30, No.
7;
Mem. Acad, (1884} 12, 203. W. A. 15, 45. See also (1883) 31, No. 14.Wiillner,P.
H. C. Vogel,144, 481.2
P. A. (1872) 146, 569.
A.
135, 497;
137, 337;
W.
A. 14, 355.
Seabroke, P. M.
[4]
43, 155.
Balmer,
W. A.
(1885) 25, 80.8
Astrophys. Astrophys.
J. J.
(1897) 5, 92.
(1897) 5, 95.
Science (1897) Science (1897)
5, 726. 5, 726.
I
30
SPK C'7'A' UM A A 'A L YSIS.
power: it consists of bands composed of water- vapor lines, The and situated between the red end and the ZMine. of the rain-band has been used by Piazzi-Smyth, presence1
Capron, Grace and others as a means of prognosticating rain. s Janssen investigated the absorption-spectrum of steam contained in long tubes under considerable pressure, and
2
Schonn
Anit
states that pure water exhibits an absorption-band. emission-spectrum consisting of numerous lines in theis
4
ultra-violet
through the electric arc;also
obtained by burning hydrogen in air, or passing it has been measured by Huggins,5
by Liveing and Dewar, who distinguished five series The first, between wave-length 3268.2 and 3063.7, of lines. 16 lines; the second, from 3057 to 2812, contains aboutandI
comprises 180 lines; the third, from 2807 to 2609, contains 141 lines; the fourth series, from 2606 to 2450, has 88 lines;
and the
fifth
series includes
79
lines
between wave-length
2449 and 2268. Elementary line-spectrum:[C or Ha] 6563.04 [F or H/3] 4861.49 [G or [H] 3970.25 [a] 3889. 15[ 2 ] 5890. 19*4983.53
5682.86
4979-30
3303.07
3302.47
2680.46
STRONTIUM.Mitscherlich obtained the line-spectrum by the use of the oxyhydrogen flame it is also produced by the passage of;
sparks through a solution of the chloride, but the best effects are given by the volatilization of the chloride in the electricarc.
This was the method employed by Kayser and Runge. 3 In the Bunsen flame the strontium haloid compounds chiefly
exhibit their individual spectra, together with the band-spectrum of the oxide, and the blue line, A. 4607.5, of the metal.
=
1
T. R. S. E. (1857) 21.
167.
Bunsen and Kirchhoff, P. A. 110 1890. Kirchhoff, A. B. A. 1861. Rutherfurd] Attfield, P. T. 1862, 221. Silliman's Journ. [2] 35, 407. Huggins, P. T. 1864, p. 139. Wolf and Diacon, C. r. 55, 334. Mtiller, P. A. 118, 641. Thalen, N. A. S. U. (i868>Kayser and Runge, A. B. A.Lecoq de Boisbaudran, Spectres lumineux (Paris, 1874). Lockyer 29, 140. Cornu, Spectre normal du soleil (Paris, 1881). Bunsen, P. A. 155, 366. Liveing and Dewar, P. R. S. 28, 367, 471 (1879) De Gramont, C. r. E. Becquerel, C. r. 94, 1218 97, 72. 29, 398, 402.[3] 6.
2
P. R. S. (1879)
;
;
(1896) 122, 1411, 1443. 8 A. B. A. 1891. See
also
Kirchhoff, A. B. A. 1861.p. 139.
Mtiller,
Bunsen and Kirchhoff, P. A. 110, P. A. 118, 641. Huggins, P. T.;
167.
1864,
Mascart, Annales de 1'Ecole normale (1866) 4. Thalen, N. A. S. E. Becquerel, C. r. U. (1868) [3] 6. Lockyer, P. T. 163, 639 164, 311. 96, 1218 (1883) 97, 72. Liveing and Dewar, P. T. 174, 217. Rydberg, W;
A. (1894) 52, 119.Visible also in the flame-spectrum.
SPECTRA OF THE ELEMENTS.Arc and spark6550.53
I&3
spectra:
164
SPECTRUM ANALYSIS.
The band-spectrum is desired. spectrum when it is not of feeble sparks through a Geissler obtained by the passage Salet produced it by volatube containing sulphur vapor. or one of its compounds, in a hydrogen tilizing sulphur, it to impinge on a plate of metal or cooled'
flame,
by allowing of water was marble, on to the other side of which a stream
This spectrum was mapped by Salet, and by Pliicker and Hittorf, but the observations are limited to the and are too inaccurate to show more than the visibledirected.
existence
region, of the
bands.
The
flame
of
burning sulphur
exhibits a continuous spectrum which extends far into theviolet.
Line-spectrum:5660.7 5342.6
5640.35320.1
5604.9 5215.44902.8
5562.4 5201.1
5508.3
547*-4 5103.7
5451.9 5033.3
5439-
543O.7
5M3-34816.6
5013.5
4926.0 4464.7
4919.4
4885.4
4715.8
4552.3
4525.5
4994-7 4485.9
2
Band-spectrum. violet, but shading536652215191
Bands sharply bordered towards thetowards the red (Salet):49915041
off
5089
4946
4841
4796
4656
4616
4471
TANTALUM. Thelines of this
element were too feeble for Thalen to3
measure, but Lockyer observed eighteen of them in the arc4000 and 3900. spectrum between A
=
TELLURIUM.obtained by passing sparks between electrodes of the element, and has been measline-spectrum oftelluriumis
The
A. c. p. [4] 28, 37. C. r. (1869) 68, 404. See also Hasselberg, Bull. Acad. imp. St. Petersb. (1880) 11, 307. Astronomy and Astrophysics (1893), 12, 347. Mulder, J. pr. Chem. (1864) 91, 112. Ditte, C. r. 73, 559. Lock1
yer, P. R. S. 22, 374.300.
C.
r.
73, 368.p. 272.r.
Gernez, C. r. (1872) 74, 803. Ciamician, Wien. Ber. 77, 839
Angstrom,;
82, 425.
P. A. 137, Schuster, B.
A. R. 1880,
Ames, Astronomy and Astrophysics28, 37.C.r.
(1893),
12.
De
Gramont, C.9 8
(1896) 122, 1326.
Salet, A.
c. p. [4]
(1874) 79, 1231.
P. T. 173, 561.
SPECTRA OF THE ELEMENTS.1
I6 5
ured by Huggins, and Thalen in the visible region, and by 3 Salet * produced a Hartley and Adeney in the ultra-violet.
8
band-spectrum by passing a discharge through a Geissler tube of hard glass containing tellurium; to facilitate heating, the tube was covered with metal. The spectrum consists ofthe red, and channelled spaces in the green and blue; they are sharply bordered towards the violet, and shade
bandsoff
in
towards the red.
The same spectrum
is
produced by
Gernez 5 investivolatilizing tellurium in a hydrogen flame. gated the absorption-spectra of tellurium chloride and bromide; they consist of channelled spaces, the former in the green and orange, the latter chiefly in the red and yellow.Spark-spectrum6438.2:
1
661
SPECTRUM ANALYSIS.
2 Huggins, and Thalen, the ultra-violet region by Hartley and 8 4 The arc-spectrum has been measured Adeney, and Cornu. and Dewar, 6 and more recently by Kayser and by Liveing 6 Runge, who usually obtained it from the metal, but occa-
sionally used the chloride; they The limits 63O/f/u and 2io,/u/w.
photographed it between the numerous lines in the spark-
spectrum between 650/4^ and 3OOyw/* are almost all absent from the arc-spectrum. With the exception of the green line at 535W> an d a faint line at 553A
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