12' Dr. Wollaston's Synoptic Scale 
there will remain 66 , g as the apparent equivalent of dry 
nitric acid. Consequently, I have no hesitation in preferring 
the estimate * to be obtained from Richter's analvsis of 
nitrate of potash, which gives 67,45, from which if we subtract ' 
one portion of azote 17,54, there remain 49,91, so nearly 5 
portions of oxygen, that I consider the truth to be 17,54 + 
or 67,54. 
From this sketch of the mode in which such an inquiry may 
be pursued, wherever it is necessary to make any original 
experiments, it will be fully understood what is meant by 
equivalents, and in what manner the series might be conti- 
nued. I have, however, in most instances drawn my infer- 
ences from former analyses, and indeed in all, where I could 
find coincidences between different authorities sufficient to give 
confidence in their results. 
But with respect to oxalic acid, I again found a difficulty in 
deciding among the discordant results of different analyses, 
and was obliged to have recourse to direct experiment. 
100 grains of bin-oxalate of potash (commonly called salt 
of sorrel) were subjected to a degree of heat sufficient to de- 
stroy the oxalic acid, and to convert the salt into a subcarbo- 
nate of potash. A quantity of muriatic acid was then poured 
on this residuum, and afterwards saturated with carbonate of 
lime; and an equal quantity of the same acid was saturated 
with carbonate of lime alone. By the excess of carbonate 
dissolved in the latter instance, it was found that 100 bin-oxa- 
late was equivalent to 40,9 carbonate of lime ; and hence the 
equivalent to 63 carbonate of lime will be 154 of the bin- 
oxalate of potash. After deducting 59,1 potash, the remainder 
* 46,7 : 53^3 :: 59,1 : 67,45 quoted in Mem. d’Arcueil, II. 59. 
