FOODS ANIMAL PRODUCTION. 1073 



FOODS— ANIMAL PRODUCTION. 



A digest of metabolism experiments in which the balance of 

 income and outgo was determined, W. O. At water and C. F, 

 Langwobthy (U. 8. Bept. Agr., Office of Experiment Stations Bui. 45, 

 pp. 433). — In view of the tact that some of the experiment stations 

 are carrying on metabolism experiments, the attempt was made to 

 gather as many as possible of such experiments made in the United 

 States and other countries up to 1895 with man and animals in which 

 the balance of income and outgo of matter and energy was determined. 

 The balance of matter is usually expressed in terms of nitrogen, with 

 or without mineral matter; or nitrogen and carbon, with or without 

 mineral matter, oxygen or hydrogen. The balance of energy is 

 expressed in terms of heat. Over 3,600 individual tests or averages 

 are included in the compilation. Of these about 2,300 were made with 

 man, about 400 with cattle and horses, 950 with sheep, dogs, and other 

 domestic quadrupeds, and 51 with poultry and doves. In about 3,400 

 experiments the balance of nitrogen and in about 300 the balance of 

 carbon was determined. 



The experiments with men, women, and children included in the com- 

 pilation were made under various conditions of health and disease. 

 Those with animals were usually made under normal conditions for the 

 study of various economic problems, although some were made under 

 other conditions for special purposes. In compiling the results the 

 date and original source of publication of the investigation, the 

 observer, the subject with age and weight, food consumed, duration of 

 experiment, and the nitrogen (or nitrogen and carbon with or without 

 other elements j in the food and excretory products are included in 

 tables. In text accompanying the tables the experiments are described, 

 the methods followed are given, and the deductions drawn from the 

 experiments are cited. 



The experiments with man in which the nitrogen balance was deter- 

 mined are arranged in three general groups — (1) healthy subjects, influ- 

 ence of diet; (2) healthy subjects, influence of other conditions than 

 diet; and (3) diseased subjects. The first group includes experiments 

 with a vegetarian diet, milk diet, bread and other single-food materials, 

 alcoholic beverages, kephir, koumiss, peptones, and similar prepara- 

 tions, to determine the amount of protein required, and miscellaneous. 

 The second group includes experiments with fasting subjects, drugs, 

 and on the influence of muscular exertion, massage and faradization, 

 baths and enemas, pregnancy, childbirth, menstruation, copious and 

 diminished water drinking, and compressed air. The third group 

 includes specific infectious and constitutional diseases and diseases of 

 the digestive system, respiratory system, circulatory system, blood and 

 ductless glands, kidneys, nervous system, and bones. The experiments 

 with man in which the income and outgo of carbon was determined, 



