304 CARNEGIE INSTITUTION OF WASHINGTON. 



nishes enough water-soluble vitamine for normal growth of rats, the 

 14 grams of milk solids which are needed to promote similar growth 

 is obviously a relatively large amount. 



These results confirm Hopkins's statements respecting the effect on 

 the growth of young rats of the addition of milk to artificial diets; but 

 the amount which we were compelled to add to obtain normal growth 

 was, for some unknown reason, considerably larger than he stated to 

 be needed. According to our experiments, only when milk sohds 

 constitute at least 25 to 30 per cent of the total solids of the diet can 

 these be depended upon to furnish enough of this indispensable food 

 accessory to promote approximately normal growth when no other 

 source of this vitamine is present. Knowledge gained by these experi- 

 ments has been utiUzed in connection with the shipment of dried milk 

 abroad, and also its use in feeding children in New York City. 



Hens' eggs have also been studied as a source of water-soluble 

 vitamine, and to our surprise we have found that when they are the 

 sole source of this vitamine the diet must contain at least 20 per cent 

 of commercially dried egg solids if normal growth is to be maintained. 

 Animals which inherit the capacity for very rapid early growth, and 

 consequently eat abnormally large amounts of food, can grow on diets 

 containing smaller percentages, but in such cases the absolute amount 

 of vitamine consumed is correspondingly large. Since the egg powder 

 used for these experiments was dried by the same process as was used 

 in making the milk powder above referred to, we have no reason to 

 suppose that the vitamine was thereby damaged. It remains to be 

 ascertained, however, whether or not this is the case. 



An extensive series of experiments is in progress with the green 

 parts of plants which are used as food by both men and farm animals, 

 and these have already yielded unexpected results of much interest. 

 These investigations are hardly more than begun, so we are not 

 prepared to report on them in detail. They promise to yield infor- 

 mation much needed by dietitians. Work has already been begun on 

 the vitamine content of tubers and it is expected to enlarge the scope 

 of these experiments as supphes become more available. Attention 

 is also being given to the distribution of vitamines in different parts 

 of seeds, and already much has been done in this field in connection 

 with a substantially completed study of the nutritive value of the 

 wheat kernel. 



Positive knowledge respecting the nutritive value of the three parts 

 of the wheat kernel into which it is separated by the modern miller 

 has become of special importance, owing to the present scarcity of this 

 grain and the necessity of using available supplies most economically. 

 We have, therefore, thought it desirable to study the relative nutritive 

 value of each of the three parts of the wheat kernel; and results have 

 been obtained which should be helpful in deciding to what extent these 



