1813] De/i?iite Proportions in Chemical Combinations. 45 



Number of W: ight of an 



atoms, integrant particle. 



23. Pbosphureted hydrogen . .3 h + \ p 



24. Sulphureted hydrogen . . A h + I s 2' 132 k 



25. Sulphuret of carbon lc +2s 2*751 ' 



26. Carburet of phosphorus m 1 c + \ p 



27. Phosphuret of sulphur . . .1 p + I 5 3*320 n 



28. Potassium 5*000 ° 



of 3 atoms of hydrogen and 1 atom of phosphorus. But I can 

 hardly believe that an atom of phosphorus can be capable of 

 condensing so great a quantity of hydrogen. At any rate the 

 great variation in the specific gravity of this gas demonstrates 

 that two or more different gases are still confounded under the 

 same name. Dalton has supposed it a compound of 1 atom of 

 hydrogen with 1 atom of phosphorus; but this is not very likely. 

 I suspect it to be usually mixed with hydrogen gas. 



k Hydrogen gas is converted into sulphureted hydrogen gas 

 without undergoing any change of volume. Hence its compo- 

 sition is known by subtracting 2*23 the weight of J 00 cubic 

 inches of hydrogen gas from 35*8!), the weight of 100 cubic 

 inches of sulphureted hydrogen. This gives us its constituents 

 2*23 hydrogen and 33*66 sulphur. Now 2*23 : 33*66 :: 0*132 

 : 1*9924. The fourth proportional ought to have been 2, to 

 agree exactly with the weight of an atom of sulphur, as given in 

 the table. The difference is only 38 ten thousandth parts, which 

 is too inconsiderable to deserve any attention. Hence I conceive 

 the constitution of sulphureted hyd ogen to be perfectly deter- 

 mined. 



1 This is the compound formerly called alcohol of sulphur, 

 and supposed to be a combination of hydrogen and sulphur. 

 Berzelius and Marcet, as well as Thenard and Vauquelin, have 

 determined its real nature. If the statement in the text be cor- 

 rect, it ought to be a compound of 81*2 sulphur and 158 carbon. 

 Now Berzelius and Marcet found 84*83 sulphur and 15*17 

 carbon, which is as near as could be expected. Hence there can 

 be no doubt respecting the constitution of this substance. 



m We have no data to determine the constitution of this com- 

 pound, though there can be no doubt that it exists Probably 

 there may be 2 atoms of phosphorus in it to 1 of caibon ; but I 

 did not venture to state that opinion in the table, because phos- 

 phorus does not unite in that way in other caves. 



" The two substances in ty be melted together in various pro- 

 portions; hut they remain liquid at the lowest temperature when 

 I "() sulphur and 66 phosphorus arc melted together. Hence I 

 conceive that to be the most intimate combination, and have- 

 accordingly stated it in the table. 



• From the experiments of Davy, compared with those of 



