The Collaborative International Dictionary of English v.0.48:

Faints \Faints\, n. pl.
   The impure spirit which comes over first and last in the
   distillation of whisky; -- the former being called the strong
   faints, and the latter, which is much more abundant, the weak
   faints. This crude spirit is much impregnated with fusel oil.
   --Ure.
   [1913 Webster]