340 On the Ednlcoration of Fish. Oil, 
Observations on Process the Third . 
First , This is most advantageously performed on 
train-oil, called vicious whale-oil ; and the more putrid 
and foul it may be, the greater will be the proportionable 
improvement, especially if there be no mixture of the 
other kinds of fish-oils, particularly the seal, which do 
not admit of being edulcorated perfectly by means of 
heat, but require other methods : but when the vicious 
oil is pure from admixture of others, however stinking it 
may be, the bad smell will be removed by this process 
duly executed, and the brown colour changed to a very 
light amber; and these qualities will be much more per- 
manent in this than in any crude oil, as it will not, from 
the degree of purity to which it is brought, be subject to 
putrefy again under a great length of time, whether it be 
kept open or in close vessels. 
The oil in this state will burn away without leaving the 
least remains of foulness in the lamp; and, being ren- 
dered more fluid than before, will go further, when used 
in the woollen manufacture, than any other kind, and 
will be much more easily scoured from the wool. 
If, nevertheless, there be any branches of the woollen 
manufacture which require the use of a more thick and 
unctuous oil, this may be rendered so by the addition of 
a proper quantity of tallow or fat, of which a certain pro- 
portion will perfectly incorporate with the oil, the fluidity 
and transparency being still preserved, as well as all the 
other qualities that render it suitable to the intended pur- 
pose. This may be most beneficially done by adding a 
proper quantity of the refuse grease of families, common- 
ly called kitchen stuff, which being put to the oil, when 
moderately heated, will immediately dissolve in it, and 
let fall also its impurities or foulness to the bottom of the 
