22-1 REPOKT OF COMMISSIONER OF FISH AND FISHERIES. 



bags, and so on, layer after layer, until 15 or 20 bags have been piled 

 up. Ileshvy pressure is then applied and continued 10 or 12 hours, 

 when practically all the oil drains from the bags, leaving behind an 

 unctuous mass of the consistency of tallow or butter, composed of 

 nearly pure stearin, with a small quantity' of debris and fibers. The 

 quantity of stearin removed depends on the temperature at whicli 

 the congealed oil is pressed. At the usual temperature of 28° to 30° 

 F., about 1^ pounds are removed from each gallon of crude oil, the 

 latter weighing about 7| pounds. The stearin is sold at 5 or 6 cents 

 per pound and is used by soap- and candle-makers and as a tallow 

 substitute in leather-dressing. 



Medicinal cod-liver oil should be exposed to the air as little as pos- 

 sible during the whole process of extraction, filtering, and pressing; 

 and as soon as the last operation is completed, it should be placed in 

 shipping packages and stored in a cool place until marketed. This 

 oil has a greenish tint, is almost tasteless and odorless. For the pur- 

 pose of making the oil lighter in color, it is sometimes bleached by 

 exposing it in a thin layer to the sun's rays for an hour or more. 

 Bleaching medicinal oil is an objectionable process, resulting in no 

 particular benefit, and, on the contrary, is productive of much harm 

 when long continued. 



The style of the package in which medicinal oil is placed is of much 

 importance. Since cod oil readily acquires the flavor of wood and 

 becomes discolored thereb}^ glass or metal receptacles are preferred. 

 Tin is much the best material when glass is not used. The Norwe- 

 gians use tin-lined barrels. When wooden barrels are employed, 

 white oak is preferable to other varieties. 



During recent years many manufacturing pharmacists have pre- 

 pared cod-liver oil in such a manner as to overcome the disagreeable 

 flavor and the even more objectionable gastric disturbance which so 

 frequently follows its use. These products are mostly in the form of 

 emulsions, gelatinous capsules, with sirups, creams, jellies, etc. 



Furthermore, some pharmacists remove the so-called" active prin- 

 ciples" in cod-liver oil, the oil itself being subsequently used for tech- 

 nical purposes. These "active principles" are extracted hy means 

 of an alcoholic menstruum, then concentrated by evaporation and 

 dissolved in wine. They are placed on the market under various 

 proprietary names. In some factories the fresh livers, rather than the 

 oil, are used in manufacturing the "active principles," since the latter 

 are alleged to occur in far greater abundance in the liver tissues than 

 in the oil. According to an account given b}^ the proprietor of one of 

 these preparations, the livers are thoroughly minced in a steam-power 

 chopping-machine and macerated for several days in large stirring 

 machines of special design, a menstruum being employed consisting 

 of diluted alcoh(jl containing a small quantity of citric acid. The 

 extract is then drawn off and concentrated in vacuo at a temperature 

 of 40° F. When the liquid is reduced to about the consistency of 



