That mixture of bodies known as fusel oil has already been described.

Distilled spirit contains notable proportions of fusel oil, probably three-tenths of 1 percent would represent the general average.

A distillate from potatoes contains less of these congeneric products, with the probable exception of amyl alcohol, than distillates from grains and fruits. For this reason a distilled spirit from potato has never become a popular drink, because it does not develop the aroma and taste which make a distilled spirit a desirable beverage.