muriate. 



610 ON VEGETABLE ASTRINGEKTS. 



Two varieties Tn speaking of the muriate of tin it is necessary to oh~ 



or muriate • . J 



©f tin : serve, that there exist two well known varieties of this suit, 



which differ, both in the relation of the acid to the metal, 

 and in the state of oxidation of the metal itself. The latter 

 is perfiaps the more essential difference, and it is that to 

 '■which their characteristic effects upon the oximuriate of 

 mercury, and the nitromur'ates of gold and platina, are re- 

 ferred. Both the muriates of tin seem to contain an excess 

 of acid, or to be in the state of supermuriates, but it will be 

 sufficient at present to distinguish them by the titles of mu- 

 riate and oximuriate of tin. The muriate is formed by 



the muriate, s i m .p]y boiling tin in muriatic acid, and preserving it care- 

 fully excluded from the atmosphere, and keeping a small 

 quantity of the undissolved metal immersed in the fluid. 



ami the oxi- The oximuriate is procured, either by permitting tin to dis- 

 solve in the nitromnviatic acid, or perhaps more accurately, 

 by forming a nitric oxide of tin, and then dissolving this 

 oxide in muriatic acid ; this latter is the method that T have 

 generally adopted. In order to ascertain, that the fluids are 

 accurately formed, it is proper to examine their effects 

 upon the oximuriate of mercury, and the nitromuriates of 

 gold and platina ; the muriate of tin, in consequence of its 

 strong affinity for oxigen, throws down from the first a gray 

 powder, from the second, what has been called the purple 

 powder of Cassius, and from the platina, a reddiah brown 

 precipitate. The oximuriate of tin has no effect upon these 

 solutions. I have not observed, that any difference ha3 been 

 noticed in the effects of these two muriates upon astringent 

 infusions, nor indeed is it stated which of them has been 

 ■employed*, yet their action is by no means identical. As I 



Oximuriate- have found the muriate of tin a less delicate reagent for the 



preferable re- different infusions than the oximuriate, I have employed the 



water, is subject to mould ; a fact which 1 have had occasion to notice, and 

 which seems almost incompatible v.- ith Lis opinion of the connection be- 

 tween the mould and mucus. 1 haye also found, that Mr. Hatchett's ar- 

 tificial tan is capable of moulding 



* Davy, Proust, and others denominate the substance upon which they 

 operate the muriate cf tin ; but f.cin the effects which it produced, I ap- 

 prehend it must have been either what I have styled the oximuriate, or a 

 fixture of the two. 



latter 



J\wts cf their 

 bein<: accurate- 

 ly formed. 



