INTRODUCTORY 39 



later) in rats kept on an artificial diet. These experiments were 

 intended to show that the growth substance could not be a vitamine. 

 We do not yet know the chemical nature of the substance in butter, 

 but there is nothing to disprove the conception that this substance 

 contains nitrogen and may be classified as a vitamine, especially 

 when it is remembered in what small amounts it may be active. 2 



Working with Macallum (81) on the fractionation of butter, we 

 demonstrated that when we followed the procedure of Osborne and 

 Mendel, and dissolved large amounts of butter fat (about 12 kilos) 

 in acetone and shook out this solution with dilute hydrochloric acid, 

 we found 23.4 mgm. of nitrogen in the extract; after hydrolysis of 

 the fatty residue with dilute hydrochloric acid, an additional 22 mgm. 

 was obtained. It is quite obvious that it is impossible to remove 

 all the nitrogen from butter with the above procedure. In spite of 

 these findings, it is true that butter is poor in nitrogen and therefore 

 it must contain a substance that is active in minimal amounts. 

 McCollum and Davis (82) endorsed this opinion, inasmuch as they 

 doubted the absence of nitrogen in butter. In order to answer the 

 question, Osborne and Wakeman (83) conducted another experiment 

 with butter and found that it contained traces of nitrogen and 



2 Later on, McCollum and Kennedy (78) sought to introduce the classi- 

 fication, "water-soluble B" for the antiberiberi vitamine and "fat-soluble 

 A" for the antirachitic vitamine; lately, Drummond (79) used the term "water- 

 soluble C" for the antiscorbutic vitamine. Regarding this matter, I have 

 attempted to show (80) that these designations are incorrect, chemically 

 and logically. It would be totally inaccurate to differentiate substances 

 extracted from complicated mixtures by their solubility in certain solvents. 

 It would seem to be of importance to replace, in the English publications, 

 such designations as "growth-promoting, water-soluble, accessory B factor," 

 by something more simple. For this purpose, I suggest, at least for the present, 

 the adoption of the following nomenclature: 



Vitamine B for the antiberiberi vitamine 

 Vitamine A for the antirachitic vitamine 

 Vitamine C for the antiscorbutic vitamine 



These letters are already used very often in the English literature, and the 

 nomenclature to be used in this book is suggested as being simple and time 

 saving, particularly in indexing the literature. Since this has been written, 

 a note by Drummond (80a) has appeared in which the same kind of nomen- 

 clature is proposed, except that he suggests "vitamin" instead of "vitamine" 

 for the English scientific literature. I cannot agree to this change since 

 I still believe in the nitrogenous nature of these substances. 



