108 



INDEX. 



the Surinam frog,' from its earlier stages till it becomes a per- 

 fect animal, i. 55 



Irides, remarks on the formation of, viii. 258 



Iris (blue), new test colour from, xv. 161 



Iron, meteoric mass of, discovered in Brazil, ii. 205. Observa- 

 tions on the mechanical structure of, as developed by solu- 

 tion, and on the combination of silex in cast, 278 



■ clay of the Giant's Causeway, geological and chemical ac- 

 count of, iv. 160 



■ ■ ■ effects of water and oxygen in oxidizing, v. 169. vii. 55. 



Native, where found, v. 293. Different classes of ore, 295 ; 

 pyrites, ib. ; magnetic, ib. ; specular, ib.; hcematites and ar- 

 gillaceous ironstone, 296. Properties and uses of iron, ib. 



improved process for the separation of, from manganese, vj. 



153, 357. On benzoate of, 159 



uses of the refuse oxide of, vii. 1S2. Decomposition of 



water by, ib. 



magnetic ore of, viii. 351 



native of Louisiana, ix. 193. Supposed meteoric, at Aix- 



la-Chapelle, ib. Micaceous iron ore discovered, 194. Obser- 

 vation-on the preparations of, in the French Pharmacopoeia, 

 249. Test for, 408. Discovery of carbonate of, 411. 



— chromate of, found in Shetland, x. 196, 462 



in the Isle of Unst, xi. 222. Analysis of, 436. Fall of an 



iron bridge in America, xi. 385. Permeability of, to tin, ib, 



— of blue ore, xii. 38. Granular chromic ore of, analysis of, 

 xii. 39. Alloys of, and steel, with chromium, 173. On the 

 separation of, from other metals, 372. Effects of the proximity 

 of masses of, on the rates of chronometers, 374, 415. Cast, 

 curious effect of sea-water upon, 407. Oxalate of, found as a 

 mineral, 422. 



— -^ recent pyrites of, discovered, xiii. 437. 



magnetic attraction of hot, between the white and blood-red 



heat, xiv. 170. On the strength of, 223. Pipes of, preferable 



to those of lead, for pumps, 352. 

 Iron, sheet, new process for soldering, xv. 142. Analyijis of a, 



