Freju^k National Institute. S\) 



M. Vauquelin has this year made some experiments upon 

 hair *. 



The method of imitating the alum of Rome, discovered 

 last year, has been so successful that immense quantities of 

 it have been sold for true Roman alum. 



We are indebted to Messrs. Clement and Desormes for this 

 discovery; and it merely consists in calcining and re-cry- 

 stallizing it, to take its superabundant acid. M. Curaudeau, 

 however, asserts that it is still necessary to oxygenate to the 

 maximum the little iron the alum generally contains. 



But in a more recent memoir Messrs. Thenard and Roard 

 have finished the investigation of this subject : a single mil- 

 lieme of iron influences the effect of alum in dyeing : evciy 

 effort of the manufacturer ought therefore to be used to de- 

 prive it of this small quantity of iron. The oxygenation of 

 the iron is one method, as it renders it insoluble in the acid; 

 and the alums thus purified are equal in every respect to the 

 alums of Rome. 



Contati;ious miasma has been ably combated by the oxy- 

 genated muriatic acid gas. This preservative, for which we 

 are indebted to M. Guvton, is very generally oniployed. 

 M. Desorenettes ascertained its effects, by some very careful 

 experiments in tiie military hospital at Val-de-Grace : and 

 it results, from the comparative tables he has sent us, that 

 these fumigations not only prevent the communication of 

 the disease, but appear to be of great, efficacy in the cure. 



M. Pinel has been equally successful in the Hospital of 

 Salpetriere. 



The public have recently been infornud, through the me- 

 dium of the jf)urnals, how successful this preservative has 

 been in Spain, and of the presents v.hich have been made by 

 the kinnf to those who have used it. We know also the 



D 



honourable recompense given by our emperor to the prin- 

 cipal author of the discovery. 



From the journals also, and from the other extremity of 

 our continent, we have been informed of the full success of 

 the process, proposed by M. Berthollcl, to preserve water 



• Sec I'liil. M'-. vol. \ .7. p. ^.ll. 



sweet 



