RELATIONSHIP OF VITAMINES TO LIPOIDS 229 



As regards vitamine B, Cooper (614), and later Sullivan and 

 Voegtlin (615), showed that there is no relationship between the 

 lipoids and vitamine B. As for vitamine A, the behavior is quite 

 different, but still there is no reason for saying with Aron (I.e. 329, 

 616) and Stepp (617), that lipoids are essential for life. In the first 

 place, with a mixture consisting of the known lipods, lecithin, 

 kephalin, cerebron and cholesterol (Stepp, I.e. 352), only a slight 

 effect could be discerned, due perhaps to the cumulative action of 

 all the impurities. Secondly, Stepp (I.e. 351) showed that at lease 

 one type of animal, the pigeon, could live in the presence of vita- 

 mine B, without lipoids. Recently, Stepp (618) stated that dogs 

 and rats cannot live on a lipoid-free diet, upon which the animal 

 develops paralysis of the hind extremities, but not beriberi. An 

 addition of vitamine B prolongs the life of the animal but cannot 

 save it from death. This experiment was supposed to show that 

 animals die because of a lack of lipoids. Regarding the matter 

 from the viewpoint of the relationship of vitamine A to the lipoids, 

 we see that while at first the view was held that this vitamine was 

 connected exclusively with the animal fats, it was found later that 

 green leaves likewise contain large amounts of the same substance. 

 Vitamine A is supposed to be present in skimmed milk, too, and 

 since the latter is believed to be free from lipoids, the relationship 

 between vitamine A and lipoids must necessarily be non-existent. 

 In particular the question as to the solubility of vitamine A in water 

 has not yet been cleared up; besides, in the extraction of a fat with 

 water, as we have already observed, the possible oxidation is to be 

 taken into account. Myers and Voegtlin (I.e. 503) shook out the 

 vitamine of yeast with olive oil, and showed that besides the vitamine, 

 other nitrogenous substances are taken up in the oil. In this case, 

 we must regard the total oil soluble portion as lipoid or, at any rate, 

 as fat-soluble. Since it has never been shown that vitamine A is a 

 constituent of a pure lipoid, and since up to the present all purely 

 isolated lipoids have given negative results when tested for their 

 activity, there is no reason for considering vitamine A as being 

 associated with lipoids; it may ultimately be shown that this associa- 

 tion is only incidental. Cramer (619) described a new type of 

 glandular fatty tissue, which he called "lipoid gland" or "cholesterol 

 gland." This tissue, which is very rich in cholesterol and other, 

 lipoids, loses these constituents when the animal is placed on a 



