420 On lavie Comlinalions of 



and lis composition being known, it is easv to delermmo 

 the composition of the hytlrophosphorous acid, and likewise 

 the quantity of oxygen required bv a given quantity of 

 phosphorous acid to be converted into phosphoric acid j 

 for, for every volume of gas disengaged, a volume of oxy- 

 gen must have been fixed in the phosphoric acid. 



And calculating for 174 grains, 30 parts of oxyeen must 

 be fixed in the 150 parts of phosphoric acid, and 20 parts 

 of [>hosphorus disengaged in coni!)inalion with four parts 

 of hydrogen; and on the idea of rep'-esenting the pro- 

 portions in which bodies combine hv numbers, if hydrogen 

 be considered as unity, ^nd water as composed of two pro- 

 portions of hydrogen, 2, and one of oxygen 13% phos- 

 phorus will be represented by 20. 



When the compounds of ciilorine and phosphorus are 

 acted on by a small quantity of water, muriatic acid gas is 

 disengaged with violent ebullition, the water is decom- 

 posed, and it is evident that for evtrv volume of hydrogen 

 disengaged in condonation with the chlorine, half a volume 

 of oxygen must be combined with the phosphorusf ; and 

 the products of the mutual decomposition of water, and 

 the phosphoric compounds of chlorine, are iiiereiy the 

 phosphoric acid from the snblii«ate and the phosphorous 

 acid from the liquor, and muriatic acid gas; so that, the 

 quantity of phosphorus being the same, ic is evident that 

 phosphoric acid must contain twice as much oxygen as 

 phosphorous acid, which harmonizes with the results of 

 the decomposition of hydrophosphorous acid. For sup- 

 posing water to be coniposetl of two proportions of hydro- 

 gen, and one of oxygen, and the number representing it 

 17; then 174 parts of hydrophosphorous acid must consist 

 ol" two proportions ; 34 parts of water, and four propor- 

 tions of phosphorous acid, containing SO of phosphorus 

 and 60 of oxvgen ; and three proportions of phosphoric 

 acid must be foruied, containing three proportions of phos- 

 phorus CO, and sa proportions of oxygen QO, making 130, 



It is scaieely possible to imagine more perfect demonr 

 strations of the Jaws of definite combination, than those 

 furnished in the mutual action of waier and the phosphoric 

 compounds. No products are formed except the new 

 combinations] neither oxygen, hydrogen, chlorine, nor 



• Supposing 100 cubicalinches of the i^as to weigh 27 grains: 27—4 5 

 the weiglit of 200 cubical inches of hvdrogen = 2'J .5 grains. 

 • f This mode of estimation is the same as that I have adopted on a forme? 

 occasion, eicept that the nuiiiber representing oxygen is dou'uled to avoid ^ 

 fractional part. 



phosphorui 



