314 Sciejitific Intelligence, [April, 



Officers and Council for the present Year, 



Fresi(lent,-^D&\ies Gilbert, Esq. MP. VPRS. &c. &c. 



Vice-Presidents.^^'ir C, Hawkins, Bart. MP.; Sir R. H. 

 Vivian, KCB.; J. H.Tremayne, Esq. MP.; HP. Tremenheere, 

 Esq. 



Secretary, — John Forbes, MD. 



Treasurer, — Henry Boase, Esq. 



Librarian. — Rev. C. V. Le Grice, AM. 



Curator, — Edward C. Giddy, Esq. 



Assistant Secretary. — R. Moyle, Jun. Esq. 



The Council. — Joseph Carne, Esq. ; H. M. Grylls, Esq. ; W. 

 BoHtho, Esq.; W. Dennis. Esq.; R. W. Fox, Esq.; Rose 

 Price, Esq. ; J. Paynter, Esq. ; S. Stephens, Esq. ; Rev. W. 

 Veale, and T. Giddy, Esq. 



Article XI. 



SCIENTIFIC INTELLIGIiNCE, AND NOTICES OF SUBJECTS 

 CONNECTED WITH SCIENCE. 



I. Edward Daniel Clarh, LLD. FRS. &c. &c. 



In announcing the lamented death of this distinguished philoso- 

 pher and traveller, the editor is permitted to state, that a biographical 

 notice by one of his intimate friends perfectly competent to appre- 

 ciate his merits in every branch of science, will appear in the next 

 number of the Annals of Philosophy. 



II. Precipitation of Silver by Chlorine. 



The editor of the Annales de Chimie et de Physique, Vol. XVIII. 

 p. 270, alluding to a statement made by Mr. Faraday and myself, 

 that a gas was chlorine, because it precipitated nitrate of silver, 

 says in a note, " This gas could not be pure chlorine, for it would 

 not precipitate nitrate of silver ; it must have contained hydrochloric 

 acid." 



It is difficult to account for this mistake, and still more difficult to 

 suppose that it could have originated with either of the acknow- 

 ledged editors of the Annales de Chimie; to prove its incorrectness, it 

 is requisite, only to refer to the tenth volume of the same work, p. 425,; 

 and eleventh volume, p. 108, — M. Gay Lussac there states, that if 

 nitrate of silver be dropped into a solution of chloride of lime, until 

 no further precipitation takes place, the supernatant liquid, if mo- 

 derately heated, is decomposed, and oxygen gas disengaged ; and if 

 the residual matter be dissolved in water acidulated with nitric acid, 

 a portion of chloride of silver remains behind. The fact is, that a 

 portion of chlorate of silver is formed which prevents the precipitation 

 of the whole of the silver in the state of chloride ; but it is evident 

 from this very statement, that when chlorine gas is passed into nitrate 

 of silver, a portion of chloride must be precipitated. 



Nitrate of silver must, therefore, be considered as a test of th« 



