COD-LIVER OIL. 
643 
that some account of the present state of our knowledge with re¬ 
spect to the chemical nature of this oil may not be unacceptable ; 
the more so, as no account of De Jongh’s analysis of this oil has 
yet appeared in this Journal. 
It may be well to remind my readers, that while some of the 
fish-oils* * * § of commerce are obtained exclusively from the liver, 
others are procured from the adipose tissue diffused through the 
body of the animal generally: in the former, therefore, we are 
prepared to find bile constituents which are not obtainable from the 
latter. 
In fishes, properly so called, the distribution of oil in the body 
of the animal is not uniform. In the Gadidce or Cod-tribe (com¬ 
mon cod, dorse, coal-fish, pollack, turbot, ling, torsk, &c.), in the 
SqualidcB or Sharks, and in some other fishes, almost the whole 
adipose tissue of the animal is concentrated in the form of oil con¬ 
tained in the livert. On the other hand, in the salmon, herring, 
sprat, and wolf-fish, the oil is more diffused through the body of 
the animal, and the liver is, comparatively speaking, devoid of it. 
The oils obtained from the livers of the different species compos¬ 
ing the tribe Gadidce appear to be very similar in their physical 
and chemical qualities, and there is good reason for believing that 
they agree in their medicinal properties. To all of them the term 
oleum jecoris aselli \, oleum jecoris gadi , or cod-liver oil^ f is indis¬ 
criminately applied; though it is commonly used, especially in this 
country, to indicate the oil procured from the liver of the common 
* I use the term Jish-oils in its popular and commercial acceptation, and 
include under it not only the oils obtained from fishes properly so called, but 
also those procured from other aquatic animals, as the cetacea and seals. 
f Professor Owen, in his Lectures on the Comparative Anatomy and Phy¬ 
siology of the Vertebrate Animals (Part 1, Fishes , p. 242, 1846), observes, 
that “ the myriads of dog-fish captured and commonly rejected on our coasts, 
shew that the fishermen have not yet taken full advantage of this anatomical 
fact, which exposes to them an abundant source of a pure and valuable oil.” 
+ Pliny (Hist. Nat., lib. ix, cap. 28) states that there were two kinds of 
fishes called aselli, one smaller, termed callarice, the other found in deep 
water and denominated bacchi; the latter were preferred to the former. 
Yarro (Opera Omnia , p. 21, Durdrechti, 1619) says that these fishes derived 
their name aselli from their resemblance in colour to the ass. 
By some latter writers, the term asellus has been extended to several 
species of the cod tribe. Thus, the common cod is called asellus major; the 
ling, asellus longus; the coal-fish, asellus niger; the whiting, asellus albus; 
the dorse, asellus striatus; the pollack, asellus haifingo, &c. 
A few years ago, a writer in one of the medical journals, mistaking the 
meaning of the word asellus, gravely announced, that “ oil of the liver of the 
ass" had been introduced, as a remedial agent, into Germany, from Sweden! 
§ The term cod-liver oil is here used to indicate the oil obtained from the 
livers of any of the cod-tribe. In this sense it is about equivalent to the 
Latin term oleum jecoris aselli. 
