INVESTIGATIONS IN HUMAN NUTRITION. 365 



Finally, mention should be made of the increasing attention paid 

 to the task of bringing institution dietaries into accord with the sug- 

 gestions of the best authorities on nutrition; this may be seen both in 

 the emphasis laid on such questions in institutional reports and in the 

 demand for thorougiily trained dietitians. 



Such are, in general terms, the agencies by which work in problems 

 of nutrition is being carried on in the United States. In the second 

 and more specific part of this resume it is proposed to enumerate the 

 more important of the many investigations made during the last four 

 or five years. Not a few embrace more than one phase of the subject, 

 and thus put a strict classification out of the question. As far as pos- 

 sible, however, they will be grouped according to their subject-matter. 



STUDIES OF FOODS AND FOOD PRODUCTS. 



No new food products of special importance have appeared during 

 the period under consideration in this sunmiary, though some of minor 

 importance have been studied. Nutrition studies of the nutritive 

 value of well-known food materials have appeared, including dairy 

 products, fruits, meats, and other materials. 



Methods of analysis have, as usual, received a great deal of atten- 

 tion. The bulk of the work has to do with the inspection of foods 

 under pure-food laws. No attempt can be made to summarize this 

 work here, as taken in connection with other pure-food work it con- 

 stitutes a subject in itself. 



For its general interest mention should be made of the work of 

 Howard** of the Bureau of Chemistry of this Department on the use 

 of the microscope for the detection of food adulteration. 



Briggs,** of the Bureau of Plant Industry of this Department, has 

 reported a method for determining the moisture content of grain, 

 which depends upon variations in electrical resistance. It was found 

 that this factor was fifty times greater in wheat containing 13 per cent 

 of moisture than in wheat containing 15 per cent. An advantage 

 claimed for tiiis method is its rapidity, the individual determinations 

 requiring only two or three minutes. 



From numerous experiments Fries'^ reaches the conclusion that 

 carbon dioxid may be determined with great accuracy in connection 

 with determinations of heat of combustion by a modification of the 

 Atwater-Berthelot bomb. He also reports data which indicate that 

 the bomb may be equally well used for the determination of hydrogen. 



For some time confusion has existed as to the terminology of nitrog- 

 enous constituents of foodstuffs, so particular interest attaches to the 



«U. S. Dept. Agr., Yearbook 1907, p. 379. 

 b\J. S. Dept. Agr., Bur. Plant Indus. Circ. 20. 

 cJour. Anier. Chem. Soc., 31 (1909), No. 2, p. 272. 



