68 : ON THE IMPURITIES OF COMMERCIAL ZINC. 
Carbon. — With reference to carbon as an impurity of zinc, we have attempted to 
determine this single point, — Does it occur in the residue insoluble in dilute acids, 
as has been generally believed, but never to our knowledge proved? One fact alone 
renders the occurrence of carbon, or of any other non-metallic substance, in this residue 
extremely improbable. We have observed that the residues from the Silesian, New 
Jersey, Rousseau Fréres, Berlin, and Mint zincs are completely dissolved in perchloride 
of iron, acidulated with chlorhydric acid. If carbon or silica were present in any 
appreciable quantity, complete solution of the residue in this reagent could not be 
expected. In testing the residues from our various spelters for carbon, we adopted 
the following process. 
From thirty to forty grammes of the zinc to be tested were dissolved in pure dilute 
chlorhydric acid, the black residue thoroughly washed with hot water, and dried at a 
heat much below one hundred degrees. The dry, grayish powder was then ground up 
with fused chromate of lead, and the mixture was introduced into a small bulb, blown 
in a tube whose diameter was not quite a centimetre. Ata short distance from the 
bulb, this tube was drawn down to a diameter of one or two millimetres, and the ex- 
Pharm. 1836, XX. 179. Two other samples of Austrian zinc gave Wittstein, — 
| (8.) 5st GA 
Lead, pant te-  . .. 0,27 per cent. .... 0.91 per cent. 
Cadmium, pa x ^ i at po ct t 
Bon vai . trace. , €t 
Otto's Lehrbuch der Anorganischen Chemie, Dritte Auflage, III. 139. 
Jacquelain obtained from a specimen of French zine, — | 
Carbon, os cs . 4 05 —— —— — T DE 
lé." ^ e E nm PT 
Lead, 0.685 
Ann. de Ch. et Phys., 1843, [3.] VII. 208. 
The following additional analyses are cited from B. Kerls Handbuch der metallurgischen Hüttenkunde, 
Freiberg, 1855, I. 225. The original sources from which these determinations were derived by Kerl are not 
stated. 
, Lead. Tron, - Cadmium. Carbon. 
1. Belgian zinc (2d quality) . . 04 0.4 
2. Silesian “ x S 5 ‘ 0.47 0.28 R 
: | 0.2 00.97 | m" 
3. u cz x S S . 045 0.32 0.75 
4. Iserlohn “ š i : i 0.30 0.35 
a. of « s ; e e 0.25 0.41 
6. Chinese ^ (bad quality) . 0.80 1.50 
4. Lower Hartz zinc, Kin uos tue’ AO 0.73 (Also contains arsenic.) 
