AT.COHOL. 153 
only becommenced. ‘This is a peculiarity in the sorgho 
greatly to its advantage in making alcohol. 
Attenuation is the term applied to that action in sac- 
charine fluid mixtures by which they gradually lose part 
of their gravity in fermentation, and it attains perfection, 
if the wash can be brought to the same specific gravity, 
or less, than water itself. Before fermentation, the mix- 
ture being much heavier than water, is shown by the 
areometer. This change in density is owing to the sugar, 
which is denser than water, changing into alcohol, 
which is lighter; and as a mixture of alcohol with water 
must, from the difference of gravity between the alcohol 
and the water, render a given bulk of such mixture 
lighter than the same bulk of pure water, it follows that 
as the sugar in the wash changes into alcohol, the mass 
changes its gravity, or attenuates. 
In forty-eight hours, in warm weather, after the wash 
commences to ferment, examine it by pushing the head 
or scum on one side, if it has not already sunk to the 
bottom, and if you find that the bubbles cease to rise, 
and that the temperature has gone down to 70° or 75°, get 
your still ready and distil the spirit as soon as possible. 
If you leave it twelve hours after this, the vat will have 
commenced the acetic fermentation, and be in process of 
making vinegar at the expense of your alcohol. 
Since commencing this article on alcohol, I have been 
enabled to test, to my own satisfaction, the capability of 
sorgho syrup, even in an advanced ‘state of acidity, for 
making spirit.. The quantity experimented upon being 
small was against the success of the operation, especially 
in the fermentation. Yet, nevertheless, I obtaimed a 
7* 
