NUTRITION. 441 



The importance of this preliminary investigation of the alfalfa 

 plant lies chiefly in the possibility of further studying the constituents 

 soluble in the various solvents. Those extracted by water can be 

 freed from those in colloidal solution by the addition of a relatively 

 small proportion of alcohol. The non-protein, nitrogenous constitu- 

 ents, about the nature of which little is at present known, should now 

 be accessible for study under exceptionally favorable conditions. It 

 should likewise be possible to isolate definite chemical compounds 

 from the "colloidal precipitate," especially those soluble in alcohol 

 which appear to be related to the flavone pigments. 



Since the water-soluble constituents can be extracted without re- 

 moving chlorophyll and other substances directly soluble in alcohol, 

 further studies should increase our knowledge of the substances 

 soluble in alcohol and ether which, by the methods heretofore em- 

 ployed, have probably been obtained admixed with many other 

 products also soluble in water. 



The fact that hot alkaline alcohol extracts nearly all of the residual 

 protein, together with other substances heretofore inaccessible for 

 critical examination, should still further help to increase our current 

 knowledge of the chemical make-up of the plant as a whole. 



A new and fruitful field for future investigation thus appears to be 

 opened which should contribute results of importance, not only for 

 plant physiology and plant physics, but also should fill a great gap 

 in our knowledge of the chemistry of one of the most important of 

 the food products. We hope to continue our investigations in this 

 new field along the lines here indicated. 



In attempting to concentrate the water-soluble vitamin in fractions 

 having a much greater potency than that of the material from which 

 the product was obtained, or in future attempts to isolate this vitamin 

 and to determine its chemical nature, it is important to know how 

 various reagents affect its activity. We have accordingly tried some 

 experiments designed to show the effect of alkali on the potency of 

 the concentrated vitamin fraction which was described in our report 

 for last year. We have found that when dissolved in O.In NaOH 

 for 18 hours the efficiency of this vitamin was not impaired. It was, 

 however, seriously affected after 90 hours at this temperature. When 

 heated to 90° with O.In NaOH solution its activity was quickly 

 destroyed. 



These experiments confirm the observations of those investigators 

 who have reported the destruction of the water-soluble vitamin B 

 when heated with alkalies. It thus appears that in attempting to 

 concentrate, or isolate, the water-soluble vitamin B, dilute alkaline 

 solutions can be used without materially affecting its activity, pro- 

 vided a low temperature and a short time of exposure to the alkali 

 are employed. 



