THE MARCH OF MEDICINE—WINTROBE 393 
blood is maintained with difficulty owing to the lowered air pressure. 
Adequate pressure cabins or pressure tubes are required, but these 
are not yet practical or available for routine use. 
Everyone now is familiar with the need for equalization of atmos- 
pheric pressure on both sides of the ear drum. It is relatively easy 
to make this adjustment on rising to higher altitudes but the reverse 
is not accomplished as readily. ‘The commercial airlines consequently 
do not permit descent at a rate faster than 300 feet per minute. The 
dive-bomber, however, may descend one hundred times as fast. The 
pilot of such a plane is hard pressed to ventilate his middle ear. 
Speed of motion does not in itself demand physiologic adjustment, 
but acceleration, that is, changes in rate of direction of motion, has 
profound effects upon the body. Imagine, for example, the effects 
of centrifugal forces on a pilot as he pulls up from a long straight dive. 
His “jaw sags open, there is a dragging sensation on his chest and 
abdomen as the internal organs are pulled downward, the limbs be- 
come so ‘heavy’ that it is impossible to move them; the legs feel tight 
and congested as indeed they are, and vision becomes blurred. If 
the stress is continued vision is lost completely (‘blackout’) and later 
consciousness,” (6) is also lost. The effects are due in large part 
to the displacement of blood from the head to the abdomen and legs. 
These are only some of the problems which confront the medical 
scientists who have been engaged in the study of aviation medicine. 
The selection of men most suitable for aviation, the developement of 
maneuvers to meet the extraordinary acrobatics required in air war- 
fare, the invention of equipment which is at the same time efficient 
and practical, are included in their tasks. Only when the war has 
been won and some of the details are no longer military secrets, will 
we know in full to what extent these problems have been met. 
Approximately 30 percent of the casualties in battle zones are psy- 
chiatric in nature. In the management of such casualties early and 
correct treatment is of the utmost importance if lasting neuroses are 
to be avoided. Rest, supported if necessary by sedatives, good food, 
quiet and reassurance before the casualty has been removed too far 
from the battle zone have served to make it possible for 70 to 80 
percent of the combatants to return to duty. Among the Australian 
forces at Tobruk there were 207 cases of neuroses. These comprised 
for the main part states of anxiety and fear. With early treatment 60 
percent of the men were restored, fit for frontline service, whereas only 
12 percent had to be returned to Australia as permanently unfit. 
In many other ways is medical science contributing to the war 
effort. Tank warfare, for example, has its own problems. Chemical 
warfare has others, both from the viewpoint of attack and that of 
protection. Malaria is only one of the plagues endangering our troops 
