THE MANUFACTURE OP COD-LIVER OIL. 377 



statements will prove that all the light oils have, in the main, the same 

 component parts, and are consequently of equal efficiency. The, clear, 

 or colourless-transparent oil, as it is termed in the trade fto distinguish 

 it from the brown and tanner's oil, is obtained by throwing the liver, 

 directly it is brought ashore by the fishermen, into largejj wooden vessels 

 or reservoirs containing about eight to twelve hogsheads or more apiece, 

 where, after having been subjected to a uniform stirring, it remains till 

 decomposition has commenced. Under this process, the cells of the liver 

 burst, and the oil therein contained floats on the surface. By degrees as 

 the oil separates, it is tapped off, and conveyed into larger reservoirs 

 where it is clarified, after which it is run off into casks, and is then ready, 

 for trade. 



The oil first drawn off from the vessel in which the liver becomes de- 

 composed is generally of a light yellow colour, whereas that which is 

 subsequently drawn off gets gradually darker as decomposition goes on, and 

 probably absorbs some of the component parts of the blood, and acid 

 properties of the air. 



A continuous bubbling in the mass announces an important evolution 

 of gases, which are partly absorbed by the oil, and impart to it an ex- 

 ceedingly unpleasant smell, which may be perceived at a great distance. 



The method of preparing the burnt, brown, or so-named tanner's oil 

 is as follows : — the solid remains, from which no more oil can be extracted, 

 are taken out of the vessel and placed in iron kettles, and boiled till all 

 the water contained in the liver is evaporated ; the remainder of the oil 

 is then expelled, and the solid component parts Grax, Grug, or Korg* as 

 it is termed, float up and swim as a hard resinous mass on the surface, 

 which is a sign that the operation of boiling is completed. 



If during this melting process the heat has been so managed that the oil 

 has been browned only to that degree that a small test dripped from a spade 

 shows a bluish tint, the operation is considered to have succeeded, and the 

 oil to be of a remarkably good quality. It is then, like the first, transferred 

 into large reservoirs, strained, and clarified, after which it is drawn off into 

 casks, and is then perfectly ready for merchandise. 



The two sorts of oil which occur in trade are principally obtained in 

 this manner. 



The liver which the fishermen do not dispose of to the oilburners, they 

 place in casks and take with them to their homes to manufacture oil for 

 themselves. The liver is exposed to the same chance of becoming decom- 

 posed while the fishing is going on, as was the case above named in the 

 large reservoirs ; and the shaking occasioned by the motion of the boat 

 contributes to partly bruise the liver, and thus to separate the oil from it. 

 The oil thus obtained is poured off, and is often purer and freeer from 



*Korg, Grv.g, or Grax is used as a manure. It must be mixed with earth, or 

 else it will destroy vegetation. Two years ago at Hammerfest and Tromso, it cost 

 from 2s. 6d. to 4s. the comb. 



