ON THE RECTIFICATION OF ALCOHOL. 295 
marked 94.7. Thus this limit of 94 to 95 appears to be im- 
passable; at this point, the affinities of the alcohol and of the 
alkaline salt for the water, counterbalance each other. It is 
but step by step that the water is separated, and we can no 
longer hope for advantageous results from the use of the alka- 
line carbonate. It is to be remarked that, at this point, the 
the alcohol is very near to the proportions of three atoms of 
alcohol and one of water, which constitutes alcohol of 95.1°. 
However, the carbonate of potassa, is the most convenient 
agent which we can employ in the first rectification of alco- 
hol; it brings it, without loss or difficulty, to 94 or 95°. The 
salt, after the operation, can be readily made useful; besides 
which, as it is scarcely soluble, it has not, like the caustic 
alkali, the disadvantageof altering the sweetness of the product. 
Alcohol of 94° being obtained, how shall we deprive it en- 
tirely of the water which it contains? 
100 grammes of fused chloride of calcium easily raises it to 
97°, but with a considerable loss of alcohol; on adding to alco- 
hol at 94°, 150 grammes of quick-lime to the pound, it will be 
raised, by remaining several days in a stove, to 97°. It is 
proper, in this case, to decant the alcohol, and not distil from 
the deposit, for it will then lose strength. The deposit may 
then be distilled alone, and will afford a feeble product. 
Now, this alcohol of 97°, obtained by chloride of lime, or by 
quick-lime, being slowly distilted with 250 grammes of quick- 
lime to the pound, after two or three days of rest in the stove, 
will readily yield absolute alcohol. 
I afterwards attempted to act with quick-lime directly upon 
the alcohol of 94°, obtained by the alkaline carbonate. The 
following first experiment is curious from its result: 
Five pounds of alcohol of 94 were placed in a flask in a 
stove, with one killogramme of quick-lime, recently calcined 
and pulverized; the alcohol swimming over the lime at the 
end of two days, marked 99°. 
The lime and alcohol were then distilled together slowly, and 
there was obtained successive portions of alcohol of 97.5°, 
97.3°, 97.4°, 97.5°, 97.4°, 97.6°, 97.8°, 98.1°, 98.2°, 98.1°, 
