390 Mr. Hunter’s Obfer vat Ions on the 
external is the common train oil ; but the Spermaceti Whale 
differs from every other animal I have examined, having the 
two kinds of fat juft mentioned, and another which is totally 
different, called fpermaceti, of which I fhall give a particular 
account. 
What is called fpermaceti is found every where in the body 
in fmall quantity, mixed with the common fat of the animal, 
bearing a , very fmall proportion to the other fat. In the head 
it is the reverfe, for there the quantity of fpermaceti is large 
when compared to that of the oil, although they are mixed, 
as in the other parts of the body. 
As the fpermaceti is found in the largeft quantity in the 
head, and in what would appear on a (light view to be the cavity 
of the (kull, from a peculiarity in the lhape of that bone, it 
has been imagined by fome to be the brain. 
Thefe two kinds of fat in the head are contained in cells, 
or cellular membrane, in the fame manner as the fat in 
other animals ; but behdes the common cells there are larger 
ones, or ligamentous partitions going acrofs, the better to 
fupport the vaft load of oil, of which the bulk of the head is 
principally made up. 
There are two places in the head where this oil lies ; thefe 
are (ituated along its upper and lower part : between them pafs 
the noftrils, and a vaft number of tendons going to the nofe and 
different parts of the head. 
The pureft fpermaceti is contained in the fmalleft and lead 
ligamentous cells : it lies above the noftril, all along the upper 
part of the head, immediately under the (kin, and common 
adipofe membrane. Thefe cells refemble thofe which contain 1 
the common fat in the other parts of the body neareft the (kin. 
That which lies above the roof of the mouth, or between it 
and 
