224 Dr. Blagden’s Report 
added dry cauftic alkali to it, let it (land for a few days, poured 
off the liquor, and difcilled it with a fmall addition of burnt 
alum, placing the receiver in ice. By this method he ob- 
tained a fpirit whofe fpecific gravity was ,8iS8 at 6cr of heat. 
Perceiving, however, that he could not conveniently get the 
quantity of fpirit he wanted lighter than ,82527 at 60% he 
fixed upon that ftrength as a ftandard, to which he found the 
above-mentioned lighter fpirit could be reduced by adding to 
It a _44._g.th part of water ; and with this fpirit and diftilled 
water he made a feries of experiments for determining the 
fpecific gravity of different mixtures of thefe fluids in different 
degrees of heat. 
The procefs followed by Dr. Dollfuss is not here given as 
the beft poflible for obtaining pure fpirit ; nor was the relult of 
it, in fadt, the lighted: alcohol that has been procured. Some 
fpirit has been tried fince that time, whofe lpecific gravity was 
,813 at 6o°. This was furnifhed by Dr. George Fordyce, 
F. R. S. who fucceeded in bringing it to that ftrength chiefly 
by adding the alkali very hot. Care muft be taken that none 
of the cauftic alkali comes over in the diftillation. Some alco- 
hol was alfo fent, for trial, by Mr. Lewis, an eminent diftil- 
ler in Dolborn, whofe fpecific gravity, at the lame tempeia- 
ture, was ,814. 
It was with fpirit rectified from malt-fpirits that Dr. Doll- 
fusses feries of experiments was made ; but he tried feveral 
comparative experiments with fuch as had been redlified from 
rum and brandy, and found no other difference than might 
fairly be afcribed to unavoidable errors. 
Upon examining the refults of Dr. Dollfuss’s experiments 
it was perceived, that though the numbers agreed together 
tolerably well upon the whole, yet in fome places there was 
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