AQUATIC PRODUCTS IN ARTS AND INDUSTRIES. 221 



do with the general introduction of the oil as a medicine in England 

 and America. From that time to the present it has held a prominent 

 place in the confidence of iihj^sieians, and is regarded as a remedy of 

 the highest value in diseases which are marked by malnutrition, pul- 

 monary tuberculosis furnishing the most frequent occasion for its 

 employment. 



Few subjects connected with materia medica have provoked so 

 much discussion as the comparative merits of the light and the dark 

 grades of cod-liver oil. Formerly, the brown oil was considered 

 superior in efficiency to the paler sorts, and was generally favored for 

 medicinal purposes. In recent years, however, chemists have claimed 

 that analysis does not reveal any substance in the dark oil which 

 would account for greater beneficial activity than the paler grades 

 are sujDposed to possess. While many physicians yet recommend the 

 brown oil, the drift of public opinion seems to favor the pale oil, and 

 certainlj^ it is more popular with the patients. A discussion of these 

 rival claims is beyond the scope of this paper. For information on 

 the subject reference is made to A. Gautier and L. Morgues' Les 

 Alcaloides de VHiiile de Foie de Morue, Paris, 1890, and to F. P. 

 MoUer's God-Liver Oil and Ghemistry, London, 1895. 



PREPARATION OF MEDICINAL OIL. 



On account of its greater value, it is generally desirable to convert 

 the livers into medicinal rather than curriers' oil. For this grade the 

 livers must be perfectly healthy and fresh, all diseased, lean, or 

 slightly decomposed ones being rejected. On account of the necessity 

 for having the material pei-fectly fresh, it is impracticable to manu- 

 facture good medicinal oil during the warm months, and even in cold 

 weather the sooner the extraction of the oil is begun the better the 

 grade secured. Furthermore, it is desirable that the livers should be 

 fi-om cod only, those from other species being excluded. This, how- 

 ever, is not the uniform practice, and the livers of haddock, hake, 

 cnsk, etc., are sometimes thrown in with those of cod. It does not 

 appear that American manufacturers are any more prone to this 

 adulteration than those of other countries. Possiblj'^ oil from other 

 livers may be equally as eificient as cod, yet until that fact is demon- 

 strated beyond a doubt those should be rejected. 



On the New England coast of the United States, the best medicinal 

 oil is made from livers collected from the shore fishing boats, which 

 land their catches almost daily, and thus deliver them in fresh condi- 

 tion. From May to October only a small amount of the best oil can 

 be made, because of the scarcity of fish along shore during that season 

 and the danger of the material puti-efying before reaching the oil 

 factory. From October to Ma}^ the shore fishermen carefully save the 

 livers in clean barrels, and if landed within a day or two they are sold 

 for making medicinal oil, but if softened or damaged in any way they 

 are used only for curriers' oil. 



