232 Mr. Rigg'sjiiriher Observations on ultimate Analysis, 



proved mode, I will take the following case, as it will serve 

 to contrast the two processes. 



We have a mixture of the sulphates of potass and soda whose 

 united weights equal 5S ; on dissolving them in water and 

 precipitating by chloride of barium, the quantity of sulphuric 

 acid present was found to be 25. Then 53 — 25 = 28, the 

 weight of the mixed bases. Then letting, as mentioned above, 



the weight of sulphate 53 = ^; a = r84<955l , c 



of mixed bases 28 = // ; Z» = 2-28209 J ^^ ^^^^^ ' 



then 



(2-28209x28 = 63-89852) = {It b) 



(63-89852—53 = 10-89852) = {JH—h) 

 (2-28209-1-84955 = 0-43254) = {a-b) 



(Ji-^hfb\ 10-89852 ._^ ,', c , 1 



\ a-b )^ -43254 =" ^^^^ "^ '""' quantity of potass and 



{h'—x) = 28 — 25-19 =3/, quantity of soda. 



This mode it is obvious is equally applicable to mixtures of 

 barytes and strontia or lead, lime and magnesia, &c., although 

 it is evident that it will only give exact results when the atomic 

 weights of the mixed bases differ considerably from each other; 

 the greater this difference is, the more exact are the results. 

 Still, however, it is much to be doubted whether the analytic 

 chemist would not prefer the results of experiment to those of 

 calculation, excepting in those cases where the mixed bases, 

 as potass and soda, scarcely admit of quantitative estimation 

 by direct experiment. 

 22, Wilmington Square, Jan. 3, 1838. 



XXXIV. Further Observations on the ultimate Analysis of 

 Organic Compounds, By Robert Rigg, M.R.I.^ 



T N my short paper on ultimate analysis which has already 

 -*- appeared in the Philosophical Magazine, p. 31, 1 described 

 the method which I adopt in the examination of solid bodies 

 only ; I therefore now propose to submit to the analytical 

 chemist my equally simple method of analysing liquids. Pre- 

 mising that the apparatus of tubes, &c., together with the 

 black oxide of copper, are such as have been heretofore de- 

 scribed, I observe, in the first place, that the liquid to be 

 analysed is accurately weighed in a small tube, whose length 

 is from one to two inches, and whose diameter is such that it 

 easily slides within the analysing tube. Round a slender wire 



* Communicated by the Author. 



