376 Miscellanies^. 



a syrup, and then formed into a ball, with sufficient oil, and, if neces- 

 sary, a h'ttle charcoal. This being put into a crucible lined with 

 charcoal, and that placed in another, containing powdered charcoal, 

 and the whole heated well for about an hour, will yield the metal 

 chromium. 



21. On the Acidification of Iodine by means of Nitric Acid; by 

 Arthur Connell, Esq. A. M. — The methods which have been 

 hitherto followed for the oxidation of iodine with a view to the form- 

 ation of iodic acid, may apparently be reduced to three : first, The 

 action of alkaline solutions, giving rise to the formation of a hydriodate 

 and an iodate, from the latter of which the iodic acid may be sepa- 

 rated by the original method of M. Gay-Lussac, and more perfectly 

 by the recent processes of M. Serullas ;* secondly, The action of 

 euchlorine, as suggested by Sir H. Davy; and, thirdly, The action 

 of water on the perchloride of iodine, and subsequent separation of 

 iodic acid by means of alcohol, as also proposed by M. Serullas. f 

 The agency of nitric acid, under certain management, offers another 

 method, "v^ich I have been unable to observe noticed any where, and 

 which, perhaps, will be found to equal in facility of execution any of 

 the preceding processes. 



This agency may be advantageously studied on the small scale. 

 If a little iodine be boiled with a small quantity of nitric acid in a 

 common test tube about five inches long, the iodine is dissolved, and 

 a red solution formed. If the liquid be now farther boiled, and the 

 orifice of the tube kept slightly stopped with a piece of eork, the 

 iodine sublimes,, and condenses on the sides of the tube. The iodine 

 is then to be washed back again into the liquid by agitation ; the liquid 

 again boiled, and the sublimed iodine again washed back into the 

 fluid ; and this process is to be continued until no iodine any longer 

 appears, and the liquid is colorless. If the boiling be then continued 

 for a little, so as to increase the concentration of the liquid, it usually 

 becomes milky ; and if it be poured out and evaporated to dryness, 

 a white mass is left, which is iodic acid, retaining a little nitric acid. 



Having made these observations on the small scale, I proceeded 

 to try the process with larger quantities of the materials, with a view 

 to its employment as a method for the preparation of iodic acid. The 



* Annalesde Chimie et de Physique, sliii. 127 and 217. t Ibid. xlv. 63 



