339 
On the Eclulcoration of Fish- OIL 
• 
separation is difficult to be effected even with the addition 
of brine ; and the oil, when a large proportion of it is 
used, can scarcely be at all brought from its concreted 
to a fluid state but by an equivalent large proportion of 
lixiviate salt : the use of lime, therefore, alone is impro- 
per, or even in a great proportion with other ingredients. 
But when only a lesser degree of edul coration is re- 
quired, a moderate quantity, conjoined with an equal or 
greater weight of chalk, which assists its separation 
from the oil, may, on account of its great cheapness, be 
employed very advantageously : it will in this case admit of 
precipitation from the oil by the addition of brine. It 
may be also expediently used when lixiviate salt is 
employed with heat for the most perfect purification of 
oils; for it will in that case give room for the diminish- 
ing of the quantity of lixiviate salt, though the propor- 
tion be nevertheless so restrained as not to exceed what 
the proportion of lixiviate salt (just requisite for the edul- 
coration) can separate from the oil. 
Chalk has an absorbing power similar to lime, but in 
a less degree, on the putrid substance of oil : it does not, 
however, combine so strongly with the oil as to resist se- 
paration in the same manner, and is therefore very proper 
to be conjoined either with lixiviate salts or lime, as it 
renders a less quantity of either sufficient, and indeed 
contributes to the separation of the oil from them. 
Magnesia alba, or the alkaline earth, which is the ba- 
sis of the sal catharticus, and the singular earth which is 
the basis of alum, both have an edulcorating power on 
foetid oils, but like lime, have too strong an attraction 
with them to be separated so as to admit of the reduction 
of the oil from the concreted state to w hich they reduce 
it ; and therefore, as they are not superior in efficacy to 
lime and chalk, but much dearer or more difficult to be 
obtained, they may be rejected from the number of ingre- 
