PURE AND IMPURE FOODS. 



" What a Man Eats He Is." 



Edited by C. F. Langworthy, Ph.D. 



Author of " On Citraconic, Itaconic and Mesaconic Acids," " Fish as Food," etc. 



NUTRITION INVESTIGATIONS. 



The subject of food economy, always of 

 vital interest, has acquired increased im- 

 portance in this country in recent years 

 from the extensive investigations that have 

 been made and are still being prosecuted 

 in connection with and as a part of the 

 work of the U. S. Department of Agricul- 

 ture and the agricultural experiment sta- 

 tions. There had been considerable inves- 

 tigation of the food of man, as well as 

 studies of the food of domestic animals, 

 before the stations were established. Much 

 of the early experimenting was carried on 

 in connection with physiological investiga- 

 tions or other work connected with the 

 study of medicine. Some of the investiga- 

 tions, however, are directly comparable 

 with more recent work. 



The first American investigation on the 

 subject of human nutrition was perhaps 

 that prosecuted by J. R. Young in Phila- 

 delphia in 1803. It was entitled "Experi- 

 mental Inquiry into the Principles of Nu- 

 trition and the Digestive Process." The 

 author studied the nutritive value and di- 

 gestibility of such materials as sugar, gum, 

 beans, and wheat, making experiments with 

 frogs and other small animals. The article 

 summarizes the ideas on human nutrition 

 held at that time. 



With the rise of the agricultural experi- 

 ment stations inquiries into the composi- 

 tion of feeding stuffs and their appropriate 

 use in the nutrition of domestic animals 

 were undertaken, and have since been car- 

 ried on actively. Later some of the stations 

 undertook similar investigations of the 

 food and nutrition of man. The science of 

 the nutrition of man has so much in com- 

 mon with that of nutrition of animals that 

 a distinction L tween the 2 is not easily 

 made, and naturally they have been studied 

 together. These researches have been car- 

 ried on mainly in the physiological and 

 chemical laboratories of universities as 

 well as of experiment stations. 



Investigations on the food and nutrition 

 of man include the study of 2 branches 

 of the subject, which, though quite inti- 

 mately related and both valuable, are nev- 

 ertheless of importance in different ways. 

 One branch of the subject comprises a 

 study of the chemical composition of dif- 

 ferent food materials. This is purely an- 

 alytical, but is a necessary preliminary to 

 the investigation in the other branch of 

 the subject, which comprises researches 



into the laws of nutrition and the econo- 

 mic and sociological application of the sub- 

 ject. The former has to do with simply 

 the chemistry of food, while the latter has 

 to do with the physics and chemistry of the 

 nutrition of man, together with its econ- 

 omic and sociological application to peo- 

 ple of different classes in different places 

 and under different conditions. 



A considerable part of the early work in 

 the study of foods in this country was ana- 

 lytical, along the line of the chemical com- 

 position of different food materials. A not 

 inconsiderable amount of such work was 

 done between the years 1840 and i860, most 

 of which, however, is of interest to-day 

 chiefly from a historical standpoint. The 

 greatest accuracy of the work done at that 

 time was in the determination of the ele- 

 mentary composition and the inorganic 

 compounds of food products. 



The growth and development of this 

 subject in the United States has an inter- 

 esting history. Beginnings were made by 

 physicians and other scientific investigators. 

 Much of the work with which the nutrition 

 investigations of the Department of Agri- 

 culture are directly connected and out of 

 which they grew was of this nature, and 

 not a little was made possible only by the 

 generosity of private individuals. Then 

 economic institutions and Government 

 scientific departments became interested, 

 and finally the results of the work proved 

 so valuable and useful that Congress made 

 special appropriations for carrying on in- 

 vestigations in nutrition in different places 

 throughout the country. 



The particular inquirv on the nutrition 

 of man, which has developed into the co- 

 operative inquiries now being prosecuted in 

 different parts of the country under the 

 auspices of the Department of Agriculture, 

 had its inception in the study of the chemi- 

 cal composition and nutritive economy of 

 food fishes and invertebrates that was un- 

 dertaken by Prof. W. O. Atwater in 1877, 

 in the chemical laboratory of Wesleyan 

 University, at the instance of Prof. S. F. 

 Baird, Secretary of the Smithsonian Insti- 

 tution and United States Commissioner of 

 Fish and Fisheries. 



The work of which Professor Atwater 

 is in charge, is conducted under the aus- 

 pices of the Office of Experiment Stations 

 of the Department of Agriculture and is 

 carried out largely in cooperation with 

 scientific and educational institutions and 

 philanthropic organizations in different 



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