ACTION OF POTASSIUM ON AMMONIA. $45 



form, as I have found by numerous trial;?, varies according 

 as the gas employed contains more or less moisture. 



Thus eight grains of potassium, during its conversion into I>ss of the gas 

 the olive coloured substance, in ammonia saturated with ^^^^ 

 water at 63° Fahrenheit, and under a pressure equal to that 

 of 29'8 inches of mercury, had caused the disappearance of 

 twelve cubical inches and a half of ammonia ; but the same 

 quantity of metal acted upon under similar circumstances, 

 except that the ammonia had been deprived of as much 

 moisture as possible by exposure for two days to potash that 

 had been ignited, occasioned a disappearance of sixteen cu- 

 bical inches of the volatile alkali. 



Whatever be the degree of moisture of the gas, the Theinflamma- 



quantities of inflammable gas generated have always ap- . gas al ^ays 



peared to me to be equal for equal quantities of metal, to the metal, 



M. M. Gay Lussac and Thenard are said to have stated, a «d less than 



J t results from 



that the proportions in their experiment were the same as the action of 



would have resulted from the action of water upon potas- watfct « 

 sium. In my trials, they have been rather less. Thus, in 

 an experiment conducted with every possible attention to 

 accuracy ot manipulation, eight grains of potassium gene- 

 rated, by their'operatibn upon water, eight cubical inches 

 and a half of hidrogen gas: and eight grains from the same 

 mass, by their action upon ammonia, produced eight cubi- 

 cal inches and one eighth of inflammable gas. This dif- 

 ference is inconsiderable, yet I have always found it to exist, 

 even in cases where the ammonia has been in great excess, 

 and every part of the metal apparently converted into the 

 olive coloured substance. 



No other account of the experiments of M. M. Gay Lus- properties of 

 sac and Thenard has, I believe, as yet been received in this tn e substance 

 country, except that in the Moniteur already referred to; fhe attton of 

 and in this no mention is made of the properties of the sub- ammonia on 

 stance produced by the action of ammonia on potassium. P 0ta3Slum * 

 Having examined them minutely and found them curious, I 

 shall generally describe them. 



: 1. It is crystallized, and presents irregular facets, which 

 are extremely dark, and in colour and lustre not unlike the 

 protoxide of iron ; it is opaque when examined in large 



masses, 



