48 MEDICINE 



and comparative anatomy, with bacteriology, and parasitology, to 

 understand and appreciate it. 



Slowly but surely the secrets of the cause of disease which baffled 

 the search of centuries have yielded to the brilliant light of modern 

 methods. The causative agents of most of the infective diseases 

 of man and of the lower animals are now known. 



The unknown causative germs of the few remaining infectious 

 diseases will soon be discovered, and then the principles of immunity 

 and cure by inoculation or by the application of antitoxins will 

 find wider application. 



Prevention of Infection 



The recognition of the germ-cause of the infectious diseases enables 

 modern medicine not only to combat disease more rationally and 

 successfully, but it enables us to prevent them. 



In most of the infective diseases due to germs, protozoa, parasites, 

 and fungi, the causative agents have been so fully investigated that 

 we know the life-history, and what conditions are best suited for 

 the propagation and multiplication of each, and also what will 

 remove and annihilate these dangerous enemies. So the diseases of 

 domestic animals which may also infest man, for example, actinomy- 

 cosis of cattle, trichina of swine, tuberculosis of animals, chicken 

 cholera, foot and mouth disease, charbon, etc., may be entirely 

 eradicated. The experience of one hundred years proves that small- 

 pox may be prevented by proper vaccination. If universally applied 

 and repeated at proper intervals the disease would probably disap- 

 pear. 



Our knowledge of the living agents which provoke malaria, 

 typhoid fever, cholera, the plague, and the means by which they 

 propagate, develop, and the manner in which they infest man, enables 

 us, if we may command the situation irrespective of the financial 

 cost, not only to prevent but also in many localities to abolish them 

 altogether. 



The discoveries of Reed, Carroll, and Agramonti of the relation 

 of the mosquito (Stegomyia fasciata) to yellow fever has been 

 practically applied with notable success in Cuba and elsewhere. 



The study of bacteriology has developed general hygiene to a 

 high plane. The value of sunlight, pure air, and pure food are fully 

 recognized as preventives and also as rational curative measures 

 in many infective diseases. 



Unfortunately there are a few of the scourges of mankind which 

 science has not yet conquered. Pneumonia, the bacterial cause of 

 which is known, is still a "captain of death." Cancer remains uncon- 

 quered. So, too, do many of the chronic diseases, namely, the primary 



