— 177 — 
with liver weighing only 10 gr., while in others, it may amount to between 1 and 2 kg. 
The percentage of fat also, as revealed in the process of boiling down, varies greatly. 
Instances have been observed of variation from about 60 to less than 20 % of oil. 
Thorough investigation as to the size of the liver, and amount of fat contained, 
at all stages and seasons, has never yet been made; the practical industry, however, 
especially the Lofoten fishery, has furnished us with a great deal of valuable informa- 
tion as to the variations in the size of the liver and im the percentage of oil therein con- 
tained. 
In the skrei fishery, where the fish are sold by number, the quantity of liver is taken as 
meaning the number of hectolitres of liver obtainable from 1,000 fish. A quantity of liver 
stated for instance as 3, indicates that the liver of 1,000 skrei would amount to three 
hectolitres*). 
The percentage of oil is generally understood as the percentage in volume of medicinal 
oil contained in the liver. 
These two factors are of great importance in the vield of the fishery. In the first 
place, the liver is in itself a valuable article of commerce, and the value of the liver forms 
an essential part of the value of the cod. In addition to this, however, it has long been 
recognised that the state of the liver is very closely connected with the condition of the 
fish, the quality of the latter improving with the increasing proportional size of the former. 
Fluctuations in the quantity of liver from year to year. 
It has therefore long been regarded as of great importance to note and record the 
quantity of liver produced. During the fishing season, the Fishery Inspectors telegraph, 
1880 a 1590 BY 1900 5 19/0 
Fig. 106. Hectolitres of liver pr. 1000 skrei in the years 1880—1912. 
5 — 5 hectolitres. 
as often as possible, information as to the amount, and the average quantity for each year’s 
fishery is calculated as closely as possible. This last is of peculiar significance, as for 
*) This factor is often expressed in opposite terms; i. e., by stating the number of livers 
necessary to make up a hectolitre. Thus the quality of liver may be noted as 330, indicating 
that 330 skrei will be required to furnish one hectolitre of liver. In the present work, however, 
the definition given above will be followed. 
23 
