THE MARCH OF MEDICINE—WINTROBE 381 
phenomenal and have saved countless lives and prevented untold 
suffering. In spite of a very great increase in the amount of surgery 
performed, and in the extensiveness of operations in which surgeons 
now engage, the over-all operative mortality in one of the better 
hospitals in this country dropped from 16.5 percent in 1889 to 2.1 
percent in 1939 (4). These advances, as well as other discoveries 
which will be mentioned later, have profoundly influenced the pros- 
pects of the battle casualties of the present day. 
THE EVOLUTION OF DIAGNOSTIC METHODS AND OF OUR UNDER- 
STANDING OF DISEASE PROCESSES 
Less dramatic but equally important have been the advances in 
methods for recognizing disease and in the understanding of the 
disturbances which various diseases produce. The early physician 
had to rely solely on his senses of sight, touch, hearing, and smell. 
Although his powers of observation were developed to a high degree, 
and necessarily so, the interpretation of his findings was often erron- 
eous because his knowledge was so limited. Examination of the pulse 
was practiced even by the early Egyptians. Temperature was esti- 
mated with the hand applied to the chest. Santorio, an Italian of the 
sixteenth century, was perhaps the first to use a thermometer, but 
until the nineteenth century the apparatus available was cumbersome 
and was used by very few. The thermometer is one of the first in- 
struments of precision to aid medical practice, but it did not become 
a necessary part of the physician’s armamentarium until the time 
of Wunderlich in the latter half of the nineteenth century. The 
modern. simple instrument was only devised in the present century. 
Examination of the urine was also practiced in the early days of 
medicine. The Arabian physician, Avicenna, wrote lengthily on the 
subject. Uroscopy or water-casting, as it was called, became such a 
regular practice that the urinal became the emblem of the physician 
in the Middle Ages and was a favorite theme of the painter and wood 
engraver. Sometimes the urine was carried to the physician by a 
messenger and the diagnosis made “by mail order.” Although this 
method had no true diagnostic value, it was pushed to fantastic ex- 
tremes and led to the most far-reaching conclusions. It was not until 
the late nineteenth century that the chemical procedures for the ex- 
amination of the urine and of the blood, which we now use, were 
developed. 
Tapping of the chest, which is so familiar today and which has 
proved to be a very valuable aid in physical diagnosis, was received 
with ridicule and sarcasm in 1761 when Leopold Auenbrugger pro- 
posed the procedure. It is interesting that he was led to this discovery 
when he observed that the level of fluids in his native wine casks could 
