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National Resources Planning Board 



a higlJy water-resistant product, as well as the use of 

 pancreas extract for the production of soft-curd milk. 



The levels of phosphatase in milk and in blood vary 

 with the degree of infection. The phosphatase test, 

 which depends upon the heat stability of the enzyme, 

 is used in industry to determine whether milk is pas- 

 teinized at the correct temperature. 



In the first steps of commercial preparation of certain 

 antitoxins, successful use has been made of proteolytic 

 enzymes to digest and in this waj^ to remove contami- 

 nating proteins. The successful use of proteolytic 

 enzymes to separate mixtures of hormones also has been 

 carried out. 



The industries described above by no means exhaust 

 the commercial uses of enzymes, and it is not too much 

 to predict for the future still more industrial applica- 

 tions. It may be said that these substances are poten- 

 tially useful to any industry which is concerned with 

 products of a carbohydrate, proteinaceous, or fatty 

 nature. 



Hormones and auxins. — Hormones, the secretions of 

 the ductless glands of animals, play a role in embryo 

 development, in the coordination of the secretion of 

 digestive enzymes, in the function of the nervous 

 system (neurohormones), in the control of the metab- 

 olism of carbohydrates, fats, and proteins, in growth, 

 and in reproduction. Many of these regulators involved 

 in the control of vital processes in both plants and 

 animals have been isolated in a higlily purified form or 

 have been synthesized. 



The early recognition that many abnormal and dis- 

 turbed functions of man and animals ai'e the result of 

 the production of too much or too little of certain 

 endocrine glandular secretions resulted in the develop- 

 ment of methods of treatment by the injection or in 

 certain cases the feeding of gland substances. Classical 

 cases are the use of insulin for the treatment of diabetes 

 mellitus, the use of sex hormones to aid in the physiolog- 

 ical adjustment (treatment of the symptoms) at the 

 time of the menopause, and the purification of the 

 pituitary hormone used in ciiildbirth. In plant cultiu'e, 

 liormone extracts and auxins are used by florists and 

 horticulturists. 



The advent of hormones in the treatment of various 

 disorders has made it necessary for the biologist to 

 survey the hormone content of the endocrine glands of 

 various species, and thus to guide the chemist in the 

 selection of the most potent sources of a particular 

 hormone. It is the function of the chemist to isolate, 

 purify, and synthesize these active substances and of 

 the biologist to study their consequences on living 

 organisms. 



Vaccines. — Man has learned some of the ways by 

 which one biological form protects itself against the 

 predator}^ action of another. This knowledge has 



enabled him to devise ways of aiding the fonn attacked. 



The observations of Jenner made on cowpox led to 

 vaccination as a protective measure against smallpox. 

 The knowledge was not further significant, since it indi- 

 cated nothing as to the mechanism involved. It 

 remained for Pasteur to make observations on chicken 

 cholera, antlu-ax, and rabies that did reveal something 

 of the processes concerned and the road to be traveled 

 to reach other goals. The manufacture of vaccines to 

 be used in preventing typhoid fever, cholera, plague, 

 yellow fever, cattle tick (Texas) fever, blackleg, hog 

 cholera, tuberculosis in man and animals, demands a 

 high type of biological service. Research in this field 

 may lead to the prevention of many other diseases of 

 man and animals. Witness the recent development of 

 vaccination for yellow fever and for equine encephalo- 

 myelitis, a disease transmissible to man. Without the 

 former our air lines to South America would probably 

 not be permitted to operate. "Jungle yellow fever" in 

 South America now presents a diflerent aspect of an 

 old problem. Recently a peculiar type of malaria 

 brought from Africa by airplanes offers a new problem 

 for control. , 



Sera. — Protective substances such as antitoxins may 

 be produced with an appropriate stimulus, and these 

 may be used to prevent or cure disease. Antisera for 

 diphtheria, tetanus, anthrax, hog cholera, and other 

 diseases are widely used. The manufacture and stand- 

 ardization of sera demand the most exacting work with 

 the organism used to produce the stimulant, the animal 

 producing the serum, and the animals used to determine 

 the potency of the serum. It is chemical work with 

 reagents from living forms. 



Diagnostic agents. — The diagnosis of typhoid fever, 

 of Bang's disease in domestic animals, and of white 

 diarrhea in chicks is made by use of suspensions of the 

 causal organism. Tuberculosis is detected by using a 

 fraction of the cell content of the tubercle bacillus. The 

 eradication of bovine tuberculosis in the United States, 

 now nearly complete, has been accomplished bj- the 

 destruction of the infected animals as shown b}- this 

 test. The results of its use in man still show the need of 

 research directed toward the improvement of the prod- 

 uct. In each of these fields the selection of the organism 

 and its nutrition are most important, as evidenced by 

 recent work on the selection and cultivation of the par- 

 ticular strain of diptheria bacillus to be used in the 

 preparation of toxins and of the tubercle bacillus in the 

 making of tuberculin. Other examples are the Weil- 

 Felix reaction in the diagnosis of typhus fever and the 

 complement-fixation and other tests for syphilis. Two 

 diseases in which important use is made of the testing 

 of individual susceptibility are the Sliick test for diph- 

 theria and the Dick test for scarlet fever. The very 

 latest tools of the physical chemist, the ultracentri- 



