ON COD-LIVER OIL. 
143 
sulphate of soda separated by crystallization. The residual 
glycerine was compared with glycerine procured from olive- 
oii and lead, and found to be darker coloured. All these 
kinds of glycerine were decolorized by adding basic acetate 
of lead to the glycerine solution, though they again became 
coloured when submitted to evaporation. 
4. Bile constituents. — When cod-liver oil is shaken with 
water, an emulsion is obtained from which ihe oil slowly 
separates. The aqueous liquid becomes clear by filtration. 
That which had been obtained by shaking the brown oil 
with water was coloured and empyreumatic; fc but the other 
kinds of oil did not colour the water. The liquid invariably 
had a slightly acid re-action, and the oil which had been 
shaken with it was clearer, had a feebler odour, and re- 
acted less powerfully as an acid. By boiling the oils with 
water, the same results were obtained. By evaporation, 
the aqueous fluids from all the three kinds of oil yielded a 
reddish-brown extract, which, softened by heat, was slight- 
ly soluble in water, was more soluble in ether, and com- 
pletely so in alcohol. Alkaline solutions dissolved it, and 
acids threw it down again in the form of a reddish-brown 
flocculent precipitate. The extracts had a peculiar odour 
and a bitterish taste. The quantities obtained from the 
different kinds of oil were as follows : 
With cold water. With hot water. 
Pale oil . . 0.607 per cent. . 0.513 per cent. 
Clear brown oil . 0.890 « " . 0.S49 " " 
Brown oil . 1.288 " " . 1.256 " " 
When successively treated with ether, alcohol, and dilute 
spirit, all these extracts yielded the same results. 
By ether, a reddish-brown, transparent, glutinous extract 
was obtained, which, melted by heat, stained paper, and 
had the odour and taste of bile. After some time, small 
crystals made their appearance in it. It was slightly solu- 
ble in water, but readily so in ether, as well as in alcohol. 
A solution of carbonate of ammonia being added to its ethe- 
