280 On the Distillation of Spirits from Grain. 
tract regularly 55-60, and even 65 litres of spirits at 19° from 
a quintal of barley. This statement may seem exaggerated to 
the distillers of the east and the interior, who do not obtain on 
an average more than from 40 to 44 litres from the same quan- 
tity of grain, and some scarcely from 30 to 35; but it is con- 
firmed by the experience of a great many distilleries. Perhaps 
there is no art which presents anomalies more remarkable. 
It would be curious to trace minutely the causes of these dif- 
ferences; but practice has got so much the advance of theory 
in this species of manufacture, that we are still forced to reason 
about it with much timidity. The fact which I am going to 
mention as explanatory of these differences, appears to me how- 
ever sufficiently conclusive, and without pretending that it is the 
only cause, I believe it will be found at least the principal one. 
Filled with chemical doctrines, | was surprised, on frequenting 
the premises of our distillers, to see them sinking at a great exe 
pense vast pits to procure water, when they might have sup- 
plied themselves cheaply from the river, which flowed close by. 
I asked them the cause of their preference; but without being 
able to explain it to me, they'all agreed in answering that they 
still remembered too well the loss they had suffered from the 
employment of river-water ever to try it again. One person 
more observant whom I interrogated upon the quality of water 
best adapted for fermentation, answered, that it was that which 
flowed over rugged or unhewn fragments of stone. 
I had here a ray of light. I recollected the means which 
Higgins had already pointed out to the planters of Jamaica, to 
prevent the acid fermentation, and I had no doubt that our well- 
water charged with carbonate of lime, held in solution with the 
aid of an excess of carbonic acid, might have the same effect 
on the processes of our distillers, as calcareous stones have less 
etficaciously on the fermenting processes of the Jamaica planters. 
In fact, this carbonate being dissolved, is desseminated equally 
through the whole vat, and it is thereby the readier to act on 
the molecules of the acid, which develop themselves so easily in 
a very dilute fernientation, and may prevent more completely 
the progress of that acetous fermentation so much dreaded by 
distillers. 
I do not hesitate a moment in indicating this cireumstance as 
an important cause of the great superiority of our distillers ; and 
tothis lam the more induced, since experience proves that they 
have never drawn more than from 40 to 44 litres, and often less, 
from a guintal of barley, where they have persisted in employing 
Tiver-water for fermentation. 
LXIJI. On 
Bi 
