644 
COD-LIVER OIL. 
cod ( Gadus morrhua, Cuv.). It would be better, therefore, to em¬ 
ploy the term oleum jecoris morrhuce, or simply oleum morrhuce, 
when it is intended exclusively to designate the latter oil. 
De Jongh, in his Disquisitio comparatively chemico-medica de 
tribus olei jecoris aselli speciebus, published at Leyden in 1843, 
states that the Bergen (Norwegian) oil is principally obtained from 
three species, viz. the dorse ( Gadus callarias), the coal-fish ( Gadus 
carbonarius ), and the pollack (Gadus pollachius), but chiefly from 
the first. 
In general, continental writers distinguish three varieties of cod- 
liver oil, one white or pale yellow, a second brownish-yellow, a 
third dark-brown. But between the finest pale yellow or almost 
colourless oil, and the dark brown cod-oil used by curriers, there 
is an almost infinite variety of shades, so that no absolute differ¬ 
ence can be founded on colour only. 
De Jongh made, in Mulder’s laboratory, a very elaborate ana¬ 
lysis of three kinds of cod-liver oil, the properties of which he thus 
describes:— 
Three kinds of cod-liver oil are admitted and described by the 
writer just quoted; these are pale, pale brown, and brown. 
1. Pale cod-liver oil. — Golden yellow; odour not disagree¬ 
able ; not bitter, but leaving in the throat a somewhat acrid fishy 
taste; re-acts feebly as an acid; sp. gr. 0.923 at 63.°5 Fahr. 
Cold alcohol dissolves from 2.5 to 2.7 per cent, of the oil; hot al¬ 
cohol from 3.5 to 4.5 per cent.: in ether it is soluble in all pro¬ 
portions. 
2. Pale brown cod-liver oil. — Colour that of Malaga wine; 
odour not disagreeable; bitterish, leaving a slightly acrid fishy 
taste in the throat; re-acts feebly as an acid; sp. gr. 0.924 at 
63.°5 Fahr. Cold alcohol dissolves from 2.8 to 3.2 per cent, of 
oil; hot alcohol from 6.5 to 6.8 per cent. Ether dissolves it in all 
proportions. 
3. Dark brown cod-liver oil. — Dark brown is transmitted 
light greenish, in thin layers transparent; odour disagreeable, em- 
pyreumatic; taste bitter and empyreumatic, leaving behind in the 
fauces an acrid sensation; re-acts feebly as an acid; sp. gr. 0.929 
at 63.°5 Fahr. Cold alcohol dissolves from 5.9 to 6.5 per cent, of 
it; hot alcohol from 6.5 to 6.9 per cent. In ether it is soluble in 
all proportions. 
De Jongh found the principal constituents of these oils to be 
oleate and margarate of glycerine , possessing the usual properties. 
But they also contained butyric and acetic acids, the principal 
constituents of the bile (bilifellinic acid, biliful vin, and cholic acid), 
some peculiar principles (among which was the substance called 
gaduin), and not quite I per cent, of salts, containing iodine, 
