PROCEEDINGS OP UNITED STATES NATIONAL MTJSEUM. 263 



portion separated by filtration at GO^ remains briglit at all temi)er- 

 atures above that point, and lias a very slight yellowish tint, resembling 

 that of the best pale cod-liver oil. When a few drops of sulphuric acid 

 are added to a small quantity of the oil, placed in a porcelain capsule, it 

 assumes a deep brown tint, without in the first instance affording the 

 violet color which is produced under sindlar circumstances by codliver 

 oil. If, however, the mixture thus formed be allowed to remain exposed 

 to the air for several hours the violet color becomes developed. If an 

 ounce or two of the Enlachon oil be boiled with about twice its volume 

 of distilled water, and the water after being carefully separated and fil- 

 tered be evaporated to dryness, a small quantity of a brown extractive 

 matter will be left, which closely resembles the extract obtained under 

 similar circumstances from cod-liver oil. 



" The Eulachon oil readily saponifies with caustic alkali, and the soap, 

 after being decomposed with acetate of lead, yields oleate of lead to 

 ether, but the oleic acid resulting from the decomposition of this is not 

 brown like that obtained from cod -liver oil. 



" Eulachon oil, therefore, although in some respects resembling cod- 

 liver oil, differs from it in some of its chemical and iihysical characters. 

 The resemblance to cod-liver oil is, however, greater than that of any 

 other oil I am acquainted with that is not extracted from a tish liver. 



"THEOPH. REDWOOD." 



It would have been interesting if Professor Eedwood had given the 

 exact analysis of Eulachon oil, as that of the cod liver has been fully 

 given in various medical works. The student of medicine could have 

 thus been able to have compared the two together, and have found what 

 constitutes their medicinal value. 



Professor Redwood says that the oleic acid resulting from the decom- 

 position is not brown like that of the cod-liver oil. The brown color is 

 owing to the presence of a x^eculiar substance obtained by an analysis 

 of cod-liver oil by De Jough, and named by him gaduin, but it has not 

 been ascertained that gaduin is in any way connected with the virtues 

 of the oil. 



It has been thought that the action of the liver carbonizes the oil in a 

 manner and thus renders it more susceptible of being taken up and as- 

 similated by the systems of persons to whom it is administered. It is 

 not improbable that the biliary principles associated with the oil are 

 concerned in its peculiar influences. Winckler has inferred from his re- 

 searches that cod-liver oil is an organic whole, differing from all other 

 fixed oils. Eulachon oil, although a body oil, instead of a i^roduct of 

 the liver, seems to possess properties essentially different from all other 

 fish-oils, and future analysis may show that the curative imnciple of 

 cod-liver oil does not lay in any of the causes mentioned, but in some 

 hitherto undeveloped principle, which is identical with that of the Eu- 

 lachon. I find no mention of the Eulachon in the voyages of Portlock, 



