OFFICE OF EXPEKIMENT STATIONS. 283 



tion. Professor Grindley's investigation has shown that meat loses, 

 in weight when cooked, the principal material lost being water, though 

 some fat is also lost and a small amount of nitrogenous material and 

 mineral matter. The losses in weight vary with different methods of 

 cooking, as well as with the fat contents; but if the material removed 

 is utilized in the form of gravy or soup it is evident, from the stand-' 

 point of food economj', that there need be no waste of nutritive mate- 

 rial. It is commonly believed that fried meats are less digestible than 

 boiled or roast meat. In these experiments it has been found that 

 there are small differences in the completeness of digestion, but 

 additional experiments are needed before the comparative digesti- 

 bility of meat cooked in different ways can be definitely known. The 

 same statement applies to the comparative digestibility of different 

 sorts of meat. 



At the University of California, at Berkeley, Prof. M. E. Jaffa has 

 continued his special investigations of the nutritive value of fruit and 

 nuts. Seven dietary studies have been made with fruitarians con- 

 suming a diet of these materials eaten raw. Thirty-two digestion 

 experiments have been made also to learn the thoroughness with 

 which fruit and nuts are assimilated. Two of the subjects were old 

 men who had been accustomed for a long time to a vegetarian diet; 

 the others were health^' young men who had been accustomed to a 

 regular mixed diet. The rations studied consisted of single fruits and 

 combination of fruits and nuts. In conducting the experiments with 

 subjects who were used to a mixed diet especial attention was paid 

 to the transition from ordinary diet to vegetarian diet in order that 

 the conditions of the experiment might be regular. In all the diges- 

 tion experiments the metabolism of nitrogen was also studied. The 

 fruitarians appeared in good health, although their diet furnished 

 considerably less jjrotein and energy than the food of the average 

 American. The studies of the dietetic value of fruits have aroused 

 much local interest in California. They are of special interest in 

 view of the fact that fruits are regarded by many persons as food acces- 

 sories rather than actual sources of nutriment and are consumed to 

 please the palate rather than for the nutritive material which they 

 contain, although the fact is perhaps also generally recognized that 

 they supply the body with salts, acids, etc., valuable from an hj-gienic 

 standpoint. Professor Jaffa's experiments emphasize the fact that 

 fruits and nuts may be an important source of nutritive material, 

 although the fresh fruits do not furnish large amounts in proportion to 

 their bulk, containing as they do comparatively large percentages of 

 water. In dried fruits which have been concentrated by evaporation 

 the percentages of nutritive material, especiall}' carbohydrates, are 

 fairly high in proportion to the bulk. So far the investigations have 

 not taken into account such fruit food products as jams, jellies, and 

 marmalades, which, judged by their composition, may furnish the 

 bodj' with a considerable amount of nutritive material. Although the 

 investigations are not yet sufficient in extent for final deductions, it 

 may be said that those already conducted have furnished a demonstra- 

 tion of the nutritive value of fruits and nuts and shown that thej" may 

 furnish a comparatively large proportion of a nutritious diet for tho.se 

 who desire to use them thus. 



At Harvard University', Cambridge, Mass., Mr. Edw. Mallinckrodt, 

 with the cooperation of Professor Sanger, in 1900 carried on dietary 

 studies with 10 students. Some of them were obliged to live very 

 economically. Some editorial work has been done upon the report of 



