Mr. Brande on the State, ^c, 83 



This conclusion may be objected to, by supposing that the 

 lowest temperature, at which the distillations were performed, 

 was sufficient for the formation of alcohol from the elements 

 existing in the wine ; but it is not easy to conceive how this 

 should happen, without some of those other changes which I 

 have just noticed. 



It has been stated, in my former paper, that the separation 

 of alcohol from wine, by the addition of subcarbonate of pot- 

 ash, is prevented by the combination of the alkaline salt with 

 the colouring-extractive, and acid contained in the liquor. I 

 have also shortly noticed some unsuccessful attempts to sepa- 

 rate these substances by other means than distillation. 



In prosecuting the inquiry, this difficulty has been sur- 

 mounted, and I shall proceed to shew, that alcohol may be 

 separated from wine without the intervention of heat, and that 

 the proportion thus afforded is equal to that yielded by distil- 

 lation. 



When the acetate,* or subacetate-f of lead, or the subnitrate 

 of tin J are added to wine, a dense insoluble precipitate is 

 quickly formed, consisting of a combination of the metallic 

 oxide, with the acid and colouring-extractive matter of the 

 wine, and when this is separated by filtration, a colourless 

 fluid is obtained, containing alcohol, water, and a portion of 

 the acid of the metallic salt, provided the latter has not been 

 added in excess, in which case a part remains undecomposed. 



• Sugar of lead. 



f Formed by boiling two parts of sugar of lead with one of finely powdered litharge, 

 in six parts of water. The solution should be preserved in well closed phials, as it is 

 rapidly decomposed by attracting carbonic acid from the atmosphere. Even while 

 hot, a poriton of carbonate of lead is formed in it. 



t Prepared by dissolving protoxide of tin in cold dilute nitric acid, 



M2 



