French N'aiional Institute. SIX 



Mr. Davy, it should only increase one I20001I) part. Thus 

 the theory by which Messrs. Gav Lussac and Thenard ex- 

 plain the formation of potassium may be applied to the 

 iormatir)n of ammonium. This new metal, according to 

 them, is nothing but anunonia and hydrogen. 



b'mally, Mr. Davy has also directed his attention to suU 

 phur, phosphorus, pknnbago, charcoal, and the diamond* 

 The chief experiments relative to these two first substances 

 have been made on hydrogen, sulphuretted and phos- 

 phuretted uases, by means of potassium ; and he concludes, 

 from the results obtained by him, that these two inflam- 

 jnalile bodies are combinations of hydrogen, oxygen, and 

 an unknown base, and which has not yet been obtained in 

 a separate state. As to the other substances, he is inclined 

 to regard plumbago as an alloy of iron with a peculiar 

 metal which is found in charcoal combined with hydrogen, 

 and in the diamond with a small part of oxygen. 



These ideas were too strongly contradictory of those 

 which are conmionly received, not to excite the inquiries 

 of other chemists. Messrs. Gay Lussac and Thenard 

 therefore made sulphur and phosphorus the subjects of a 

 very extensive series of experiments ; and as Mr. Davy had 

 employed the hydrures in his experiments^ the French 

 chemists in the first place endeavoured to determine the 

 elements of these substances with precision. They ascer- 

 tained that sulphuretted hydrogen gas contains a volume of 

 hvdrogen equal to his quantity ; that the phosphurettcd 

 hydrogen gas contains at least one and a half of its volume ; 

 that the former of these gases may be absorbed by potas- 

 sium and sodium ; and that in this absorption there is de- 

 veloped precisely the same quantity of hydrogen which 

 the metal alone would give with anunonia and with water ; 

 lastly, that phosphureiled hydrogen gas is decomposed by 

 potassium and sodium, so that the phosphorus is combined 

 with this metal, and the hydrogen is set free. But these 

 chemists have not confined their researches to the sub- 

 stances employed by Mr. Davy : they made experiments on 

 arseniated hydrogen gas, and found that this gas acts with 

 I he new metals in the same way with phosphurettcd hydro- 

 gen gas ; and that the metallic arsenic may be combined 

 with hydrogen so as to form a solid hydruret, which has 

 the form of light flakes of a brown colour. They con- 

 cluded that sulphuretted and phosphuretted hydrogen gas, 

 as vvell as sulphur and phosphorus, contain no oxygen, or 

 at least that the experiments of Mr. Davy do not demon- 

 *trate it. They are of opinion, however, as has been al- 



U 4 ready 



