£ so 1 



Experiment Tenth. 



February 15th, 1777, 1 fet apart two Aberdeen/hire pecks 

 of potatoes by meafure, which I have fince found were 

 each equal to 36 pounds by weight, fo that th? whole was 

 72 pounds. Thefe potatoes were boiled in a cauldron till 

 they were brought to a foft pulpy ftate ; they were then 

 bruifed, and made to pafs through a ftrait riddle along with 

 fome frefh water ; the fkins being kept back by the riddle, 

 which were thrown away. The pulp was then mixed with 

 cold water, till the whole amounted to about twenty gal- 

 lons Englifh. This was allowed to cool till it attained the 

 fame temperature as would be proper for mixing yeaft with 

 wort; when fome yeaft was put to it, as if it had been 

 yeaft to wort from malt. In ten or twelve hours a fer- 

 mentation began, which continued very brifkly for the 

 fpace often or twelve hours, but at the end of that time it 

 began fenfibly to abate ; from which circumftance I was 

 afraid my experiment would fail. After waiting for fome 

 time, and in vain, warming it a little, with a view to re- 

 new the fermention, I determined to ftir it brifkly to fee if 

 it could be renewed by that means. This produced the 

 defired effecl:, and the fame operation was renewed every 

 day, and the fermentation continued to go on in a proper 

 manner for a fortnight. At the end of this time the fer- 

 mentation abated, and could not be renewed by agitation 

 or otherwife; and the liquor, having been found upon 

 trial to have acquired a kind of acid, llightly vinous tafte, 

 was judged fit for diftillation. It was then diftilled with 

 due caution, care having been taken to ftir it in the ftill, 

 until it began to boil, before the head of the ftill was ap- 

 plied ; and the fire was afterwards kept up fo ftrong as to 

 keep it boiling brifkly till the whole was run over. This 

 was intended to prevent the thick matter from fubfiding 

 to the bottom j for I was afraid that without this precau- , 



tion, 



