INDEX. 
C 
Chloro- chromic acid, how obtained, description and experiments 
on the properties of, p. 190. 
Chloro- chromic acid , analysis of, p. 195. 
, composition of, p. 199. 
Christie, S. H. Esq. On the mutual action of the particles of 
magnetic bodies, and on the law of variation of the magnetic 
forces generated at different distances during rotation, p. 71. 
, theory of the diurnal variation of the magnetic 
needle illustrated by experiments, p. 308. 
Chromates , p. 218. 
Chromic acid , analysis of by protosulphate of iron, p. 173. 
— - -, analysis of, by sulphuretted hydrogen gas, p. 164. 
Chromiron ore, analysis of, p. 227. 
Chromium, on some of the compounds of, p. 159. 
Chromium and its oxides, atomic weights and constituents of, 
p. 190. 
• arseniale of, p. 212. 
broivn oxide of, preparation and description of, p. 186. 
carbonate of, p„ 208. 
■ chromate of, p. 213. 
— ^ green oxide of, p. 162. 
muriate of, p. 204. 
— nitrate of, p. 205. 
—— oxalate of, p. 214. 
— — phosphate of, p. 210. 
pho&phuret of, composition of, p. 178. 
— - potash-tartrate of, p. 216. 
— pure metallic, description of, p. 160. 
— — salts of, account of, p. 202. 
sulphate of, p. 206. 
tartrate of, p. 215. 
Common oyster, on the propagation of, p. 39. 
, mode of breeding in, p. 41. 
Computation of the radii for correcting spherical aberration and 
colour, on the, p. 239. 
Curves for an achromatic object-glass , approximate method of 
computing, p. 262. 
