346 Contributions to Chemistry from the 
as taken and found is of course still more near. The errors 
that appear in the estimation of the chlorids would be consid- 
erably reduced, if, as usually happens, they were calculated as 
oxyds 
Here follow the formule which I have employed for caleu- 
lating the quantities of NaCl and KCl, or of NaO and KO, con- 
tained in or corresponding to any mixture of alkali-chlorids 
whose total weight and amount of chlorine are known. ue 
KCl = W x 46288 — C X 76811. : 
NaO=C X 4:0466 — W x 1°9243. 
KO W x 2:90248 = C x 48210. i 
The restlts I have obtained thus demonstrate that the indirect 
method is in all cases equal in accuracy to the ordinary separa- 
tion, while in the matter of convenience and economy of time 
there is no comparison between them. i, 
st 
Agr. XXXI— Contributions to Chemistry from the Laboratory of 
the Lawrence Scientific School; by Woucort G1pss, M.D., Rum- 
_ ford Professor in Harvard University.—No. I. A 
acid. Himly’s paper attracted little attention and was soon 10% 
gotten. ‘T'he subject was again taken up at about the same time 
by Vohl? and Slater* who a pear been unacquainted 
by these chemists differ in some particulars, especially as Te - ; 
copper and lead. More recently Chancel* has employed pate | 
Posulphite for the separation of alumina from iron, and 
_ | Annalen der Chemie und Pharmacie, xliii, 150. "3 ‘The same, xcvi, 237 
Chemical Gazette, 1855, 369, he Comptes Rendus, xhvi, Ole. ig 5 
