BIOLOGY AND MEDICINE—CHANDLER 323 
Concomitant with development of knowledge of causes of infectious 
diseases, immunology was beginning to make its contributions to the 
cure and prevention of disease. You are all familiar with Jenner’s 
discovery in 1798 of the protective value of cowpox inoculation against 
smallpox. As the result of that there is probably no one in this audi- 
ence with a pockmarked face, whereas in Jenner’s day certainly one in 
four of you would have been so marked if indeed you were alive at all. 
Jenner, however, had no notion of how his method worked; he merely 
observed that it did, and risked the ridicule of the medical world by 
saying so, and the life of his own son by testing it. 
Many decades later Pasteur, making the most of an accidental obser- 
vation, laid a foundation for modern immunology by showing that 
agents of disease can be attenuated by various means to a point where 
they are no longer capable of producing serious disease, but still possess 
the power of stimulating immunity comparable with that produced by 
recovery from a real attack. Just as bacteriology opened the gates to 
knowledge of the causes and means of transmission of infectious dis- 
eases, so the birth of immunology opened the way to knowledge of 
nature’s principal means of combatting them. 
The contributions of immunology to the cure and prevention of dis- 
ease are so numerous that [can mention butafew. Asaidsin diagnosis 
I may mention the tuberculin test for tuberculosis in cattle and man; 
the Shick test for susceptibility to diphtheria; the Dick test for sus- 
ceptibility to scarlet fever; the scratch test for allergies to pollens, 
foods, or other substances; the agglutination tests for typhoid, dysen- 
tery, cholera, typhus, and many other diseases; the Wasserman, Kahn, 
and other tests for syphilis; the typing tests for the pneumococci of 
lobar pneumonia; and many others that are less well known but no 
less useful when needed. 
As therapeutic aids I may mention antitoxins for diphtheria, tetanus, 
scarlet fever, and a number of other diseases, which have made deaths 
from some of these diseases under ordinary conditions nothing short 
of criminal negligence; the helpful injections of typed pneumococcus 
serum in pneumonia; the use of immune or convalescent. serum in 
cerebrospinal meningitis, anthrax, measles, and most recently influ- 
enza; and the life-saving properties of antivenin for snake bites. 
As preventive aids I need only call your attention to the wonderful 
records achieved by the use of vaccines against typhoid, paratyphoid, 
diphtheria, and more recently yellow fever. This once dreaded dis- 
ease is now looked upon by the United States Public Health Service 
as of less consequence than the relatively mild and tolerated dengue 
fever, merely because our Government has a bank of a million protec- 
tive doses of vaccine which it can release if ever a case occurs within 
our borders. In recent years success has also been attained in produc- 
tion of vaccines against typhus fever and spotted fever, the former of 
