414 On definite Proportions. 



in the bulb of the retort was crystallized. When brought 

 near a glass stopple, moistened with muriatic acid, it exhi- 

 bited no more vapours : consequently ihe base of ammonia 

 had been coniplelelv destroyed in .his experiment. 



Having learned, from this result, that the base of am- 

 monia cannot be exhibited pure by experia)ents with the 

 amalgam of annnoniuni, I perforn)cd several experiments 

 in different ways, in order to determine whether and in 

 what form this base can be exhibited separately. i-iM I 

 have hitherto been able to obtain no satisfactory determina- 

 tion of the f)uestion. 



I have related, in the description of my elcctroch.emical 

 experiments, performed in coumjon \\ith Dr. Pontin, that 

 the base of anmionia, combined with a small quantity of 

 mercury, forms a leaden gray flocculent amalgam, which 

 floats on water. This amalgam may be obtained without 

 the immediate operation of electrieity, if we mix the re- 

 siduum leit after the distillation of the amalgam of potas- 

 sium, with a concentrated solution of sal ammoniac, in a 

 strong and well stopped vessel. The decomposition l)cgins 

 inmiediatelv, and the newly formed amalgam swells some- 

 times to 130 or 200 times the volume of the quicksilver, 

 which remains after the complete oxidation of both the 

 bases. It emits at first a little gas ; but this extrication of 

 gas soon diminishes, and becomes at last, as the pressure 

 of the air in the vessel inpreases, totally imperceptible. 

 The amalgam then floats on the surface of the fluid, in the 

 form of a porous, round mass, putting out vegetations on 

 all sides. If we open the vessel, hydrogen gas is forced 

 out with an explosion, and the newly formed amalgam 

 begins to be decomposed, with a violent hissing. If 

 the experiment is performed in an open vessel, the base 

 of ammonia is oxidated almost the instant that it is pro- 

 duced. 



Some attempts to combine the amalgam of the base of 

 ammonia with sulphur, or with phosphorus, afforded me 

 no satisfactory results. When, for example, 1 shook the 

 amalgam of potassium with the sulphuretted hydroo;et [or 

 hydroliieatej of ammonia, I obtained nothing but the sul- 

 phuretted hydrog>:t [hydrotheatej of potass, and the usual 

 buttery amaljjain. Sulphuret of potass had no perceptible 

 eff'ect on the amalgain of ammonia, although the mercury 

 alone would have blackened it; but when the amalgam 

 shaken with sulphuret of potass, alter being washed with 

 pure water, was put into a solution of lead, it afforded evi- 

 dent marks of containing a little sulphur ; which however 



did 



