380 COMPOSITION OP AMALGAM OF AMMONIA. 



Determination of the Quantity of Hidrogen and of Am^ 

 monia contained in the Amalgam of Ammonia : by Messrs* 

 Gay-Lussac and Thenard *. 



Quantity of hi- W E took 3*069 gr. r47-4Q3 firrs-l of mercury, placed 

 drogen contain- ,, . ,, , * , . , . , 



ed in amalgam ^"®"^ *" 3, small cupel of sal ammoniac at the negative pole, 



of ammonia, and, when their, bulk was about quintupled, threw them 

 into a conical glass filled with water, in which was pre- 

 viously placed a small jar also filled. The bubbles of air, 

 that might have been adherent to the button of amalgam, 

 were at first suffered to escape, by keeping the jar close to 

 the sides of the glass; after which the jar was raised, so as 

 to let the button fall to the bottom, and all the hidrogen 

 gas arising from it was collected gradually in the upper 

 part of the jar. Six buttons of amalgam, each made with 

 a similar quantity of mercury, and treated in this manner 

 successively, produced such a quantity of hidrogen, that 

 the mercury had absorbed 3*47 times its bulk of this gas in 

 passing to the state of soft amalgam. To avoid every 

 source of errour, the bulk of the mercury employed and 

 of the hidrogen collected was measured in the same tube, 

 which was accurately graduated. 



A second experiment, made also with six buttons cf soft 



amalgam, having afforded results scarcely differing from 



the preceding, they may be considered as exact, or at 



least as approaching very nearly to the truth. It may 



happen however, that, on a repetition of these experi, 



ments, other numbers than ours maybe found; and this 



must necessarily be the case, if the amalgam were not 



made so as to obtain it soft, or so that the mercury enter^ 



ing into it should have its bulk at least quintupled. 



Quantity of am- ^^ imagined at first, that by amalgamating a given quantity 



monia contain- of mercury and deducting the known weight of the mercury 



of ammonfa! and the hidrogen it contained, we should find exactly thequan- 



tity of ammonia entering into the amalgam. But we sooii 



* Annal. de Chim. vol. Ixxiii, p. 209. Extracted from a paper 

 read to the Institute, September, 1809. 



found 



