166 Franklin Institute.

NOTE 2. Annaire pour Pan 1831, presente au Roi, par le Bureau des Longitudes; Notices Scientifiques, par-M. Arago,

Stevenson's Notes on the Illumination of Lighthouses, i848, quarto, London and Edinburgh.

Report of Select Committee of the House of Commons of Great Britain, upon Lighthouses; 1 vol. folio, London, 1845. Evidence of Alan Ste- venson.

See remarks of William Herschell on the reflection of light from surfaces of speculum metal, in the Philosophical Transactions, Vot. 90, page 64, Londvn.

(To be Continued.)

Report on R. E. .Monaghan's ~pparatus for Recording the ./tyes and 3~eays in Legislative 21ssemblies.

The Committee on Science and the Arts, constituted by the Franklin Institute of the State of Pennsylvania, for the Promotion of the Mechanic Arts, to whom was referred for ex- amination--"A method of recording the Ayes and Nays in Legislative Assemblies," in- vented by Mr. R. E. Monaghan of West Chester, Pennsylvania.--RxroRw:--

That the method of Mr. Monaghen consists in an arrangement of wires similar to that used in hanging our common house bells. Two such wires lead from the desk of each member to the desk of thc Clerk, where each one is ~tached to a lever, the free end of which carries a cutting edge or point.

Upon a suitable frame under the levers are placed lists of the members of the house, as many in number as it is desired to have copies of" the re- cord; and the levers are so arranged that the points of those attached to each desk are placed, the one before, the other after the name, and the col- umns in which the marks from these points come, are headed, the one ayes, and the other nays.

The member votes by pulling either one or the other of the wires at- tached to his desk, which are labelled aye and nay, and by so doing he immediately records his vote as many times as there are lists of members placed under the points. The marks are very distinct, and the time oc- cupied in the votiffg is reduced to that necessary for the Clerk of the House to read the names and sum up the votes of the two columns.

It is not within the proper powers of this Committee to decide upon at,y of the advantages to be derived from this method of rapidly taking the ayes and nays, except that arising from the great economy of time. The others, such as rendering the voting of members more independent, and preventing the resort to the calling of the ayes and nays, as a mere means of delay and vexation, being in their nature political. The Committee therefore confine themselves to the expression of the opinion that the ap- paratus of Mr. Monaghan fulfils the purpose for which it was intended, by making any number of instantaneous records of the votes. Mr. Mon- aghen has submitted to the Committee numerous certificates from the mem- bers and Clerks of the House of Assembly at Harrisburg, where his ap- paratus has been erected, that its results were satisfactory.

Chemical .3nalysis~ Qualitative and Quantitative. 167

The apparatus is very simple, not expensive, and easily repaired by an ordinary mechanic, and so far as the Committee know, they have reason to believe is novel. They therefore judge it worthy of approval.

By order of the Committee~

WILLL~M HAMILTOn', .3ctuary. Philadelphia, July 12th~ 1849.

B I B L I O G R A P H I C A L N O T I C E S .

Chemical.gnhlysis, Qualitative and Quantitative. By HEaRt M. No.era With numerous additions, by CAMPBELL MO~'IT. With Illustrations~

pp. 572. Philadelphia, Lindsay ~ Blakiston. 1849.

The visible objects around us are not as simple as they appear lo be, but with few exceptions are variously compounded of two or more simple or elementary bodies, that is, simple, undecomposahle, not resolvable into other bodies, accordingto the present state of our knowledge; and we have nothing to do with the conjectures as to what future chemists may accom- plish. It is the business of the chemist to resolve these compounds into their elements, to show us of which elements and in what proportion they are composed. Now there are 63 elements, of which 20 are in constant use among us, 14 employed to a eonsidesable extent, 7 of trifling impor- tance~ and 22 not used at all~ as far as we know. Since the properties of a compound are usually very different from those of its constituents~ we cannot know by simple inspection what a body is composed of, and to determine its composition is not always, indeed rarely, an easy process . - We must know the properties of each body, the manner in which it be- haves to various chemical agents, and by taking advantage of those prop- erties or behavior, in which two elements differ, we may separate them from each other. But these differences are often so slight that the difficul- ties of separation are by no means as easy as might be imagined. For- tunately most of the bodies we have to deal with contain but few elements, for if we~/~ld to decompose a compound containing some 30 of the ele- ments, the best chemist would shrink from the task~ unless impelled to it by weighty considerations. But although bodies usually contain but few emments, yet those :are variously compounded, and according to their com- position the processes of separation are devised. Hence arises the two fold division of analysis, or the chemical separation of a compound into its elements, qualitative and quantitative. By the first we determine the number and nature of the elements present, and by the second their rela- tive quantity.

Works on elementary chemistry formerly contained a few pages~on an- alysis, usually stowed away at the end of the work, and it was a mystery to the student to know how it was possible to find out all the facts repres- ented in the body of the turk . Now, however, we have many separate treatises on analysis, and among them works of considerable size. Faults they almost all have, for while one is too full, another is not full enough, while ona is too scientific for the common reader, another is rather too praeti-