376 THE MANUFACTURE OF COD-LIVER OIL. 



colonies, -where the climate is suitable, and the labour is to be had, that the 

 rape or colza cultivation will be a most valuable element of commerce as 

 well as of farming. 



ON THE MANUFACTURE OF COD-LIVER OIL, AND A NEW 

 METHOD OF PREPARING IT FOR MEDICINAL PURPOSES. 



BY PETER MOLLER. 



Although it might be supposed that the manufacture of cod-liver oil 

 was a matter of general experience, yet, not only on the Continent, but 

 also amongst ourselves in a great measure, uncertainty and erroneous 

 ideas are very prevalent both as to the method in which it is manufactured, 

 and also as to the different sorts which are met with in trade. It is not,, 

 therefore, surprising that on both these points the most opposite statements 

 are to be found in foreign newspapers, gathered chiefly by merchants 

 or travellers, who, during their stay here in the country, have managed 

 to extract very imperfect information about the matter, and have subse- 

 quently published accounts of their travels. But, as cod-liver oil has 

 of late assumed a very important position in medical practice (where it 

 will for the, future be indispensable), and can no longer be looked on 

 merely as a fashionable remedy, I have considered that my own experience 

 of its manufacture in general, and of a better method for its preparation 

 discovered by me, may not prove uninteresting. 



Originally, cod-liver oil was only used for burning in lamps, and as 

 grease ; it was prepared, therefore, solely with this view ; and it was 

 considered unnecessary to attempt or devise any^ better method for its 

 manufacture than that which had been in general use, since the days of 

 Arild to the present time. 



Proj>erly, there are only two sorts of cod-liver oil, the light, or so- 

 called clear sort ("of which there are many varieties essentially the same, 

 and differing only in shades of colour from a light to a somewhat deeper 

 brown), and the dark brown, or so-called tanner's oil. Owing to the 

 various shades of colour to be found in the former sort, it has been con- 

 ceived that this circumstance was owing to the several methods em- 

 ployed in its preparation, and thus, in consequence, each different shade 

 was supposed to possess different medicinal qualities and different com- 

 ponent parts. Oesterlen,* p. 481, mentions sixteen different sorts ; and 

 it has been believed that the light brown contained more phosphorus, 

 whilst in the darker shades iodine was the more active ingredient. In 

 Sweden, and especially in Stockholm, preference has been given to the 

 dark brown sort, or tanner's oil, as being the most efficient. The following 



*Dr. Fr. Oesterlen: Handbuch der Heilmittellehre,, 6te Aiifl. 1856. 



