1817. during the Year 1816. 37 
of gold. But 100 gold, according to Berzelius, combines with 
12°08 oxygen. Therefore, according to this experiment, phosphoric 
avid is composed of 
PTOS PNOEG ee Maaielia sop 8's a5 ns bates > <0 100 
0.872027 MB ALS-g: BS ar sie” ducts 126°94 
In another experiment 0°8115 of phosphorus reduced 13:98 
parts of silver from the sulphate to the metallic state. Hence one 
part of phosphorus combines, in order to be converted into phos- 
phoric acid, with all the oxygen capable of uniting with 17-227 
parts of silver. But 100 silver combine with 7°291 of oxygen, (See 
Annals. iv. 15.) Therefore, according to this supposition, phos- 
phoric acid is composed of 
Phosphorus ...... PROT Ae ey PIM DLO 
Oayeen peeled oe ie) ofl nl. aa 125°53 
The mean of these two experiments gives us 126°23 for the 
quantity of oxygen combined with 100 phosphorus in phosphoric 
acid. These results agree very nearly both with the experiments 
of Dulong and my own, made by burning phosphorus in an appa- 
ratus contrived for the purpose. But I do not see how they can be 
reconciled with the composition of phosphoric acid as determined by 
the combustion of phosphureted hydrogen gas, which appears to be 
the simplest and most decisive method of determining the point. 
Phosphorous acid, according to the calculation of Berzelius, is 
composed of 
Phosphorus ........ soiled allan in AL 
OTS VE EN von a bonis a <iacbe> spe Miginpsarse, Qe 
But this calculation is founded on data that appear, to say the 
least of them, very questionable. Such a result cannot be recon- 
ciled with the undoubted fact that the oxygen requisite to convert 
the phosphorus in phosphureted hydrogen into phosphorous acid is 
just one half of what is required to convert it into phosphoric acid. 
According to Berzelius’s estimates, the oxygen in phosphorous acid 
is to that in phosphoric acid as 3: 5. According to this estimate, 
the weight of an atom of phosphorus would be 3:901. Further 
researches are necessary before this obscure subject be cleared up, 
(See Ann. de Chim. et Phys. ii, 217.) 
Professor Berzelius terminates his paper by a bitter complaint 
against me for having made no use of the views which he suggested 
in his paper On the Cause of Chemical Proportions, in my Essay on 
the Theory of Definite Proportions in Chemical Combinations. He 
assures his readers that my view of the subject is radically bad, and 
that, by touching upon the theory, 1 have done much more injury 
than good to the doctrine of definite proportions. It would have 
been singular, indeed, if in a paper written and published (Annals, 
ii. 32, July, 1813) several months before his paper came into my 
possession (published Annals, ii. 443, December, 1813), 1 should 
