MANUFACTURE. T/1 preparing the oil for medi•inal purposes, only perfectly healthy livers should be used and the green-colored (or spot ted), diseased livers rejected. In former times the oil was obtained as follows. The fishermen would stow away the livers in barrels, which were kept unopened till the end of the fishing season; that is to say, from one to four months. During that time the livers would undergo putre faction, their hepatic cells, containing the oil, would burst open. and the escaping brownish yellow oil (balled pale oil) would rise to the top of the barrels and be drawn off. The livers would then be allowed to undergo further putre faction, and a quantity of dark-brown oil (called light-brown oil) would again be drawn off. Finally, by heating the disintegrated liver-resi dues thus obtained above the boiling tempera ture of water, a last quantity of oil (called brown oil, though really black) would be obt allied. This primitive method, a knowledge of the details of which would render the oil too repulsive to most patients to swallow, is still employed to sonic extent. By far the greater quantity of the oil. however, now reaching the market is pre pared in a much cleaner way by the steam process first introduced by Muller in 1853. In
stead of allowing the livers to undergo putre factive decomposition, Maier obtained the oil by simply heating for about three hours the fresh livers, which were carefully selected, cleaned by washing with water, and separated flout the gall-bladaers.
To avoid delay, the livers are often heated on board vessels, in wooden apparatus, steam being coudueted directly into the mass of livers, ally, however, the livers are heated in tinned sheet-iron vessels, either single or double walled. The single-walled apparatus is heated over large water-baths; the double-walled by passing steam into the space inclosed between the interior and the exterior walls. In all these apparatus the temperature is about that of boiling water. An improvement recommended during recent years consists in heating the livers at a con siderably lom'er temperature. for a much shorler time, and as far as possible out of contact with the air: it is asserted that in this man ner the oxidation of the oil may be almost completely prevented and that the oil would, therefore, not become rancid. nor acquire the disagreeable property of causing eructations.