between the two being the pressure pulse, we learn to interpret the
pressure pulse reading. While the average pressure pulse has
frequently been stated as 30 mm., it is probable that 35 at least,
and often 40 mm. represents more nearly the normal pressure pulse,
and from 25 mm. on the one hand to 50 on the other may not be
abnormal.

Faught [Footnote: Faught: New York Med Jour., Feb. 27, 1915, p.
396.] states his belief that the relation of the pressure pulse to
the diastolic pressure and the systolic pressure are as 1, 2 and 3.
In other words, a normal young adult with a systolic pressure of 120
should have a diastolic pressure of 80, and therefore a pulse
pressure of 40. If these relationships become much abnormal, disease
is developing and imperfect circulation is in evidence, with the
danger of broken compensation occurring at some time in the future.

It should be remembered that the diastolic pressure represents the
pressure which the left ventricle must overcome before the blood
will begin to circulate, that is, before the aortic valve opens,
while the pressure pulse represents the power of the left ventricle
in excess of the diastolic pressure. Therefore it is easy to
understand that a high diastolic pressure is of serious import to
the heart; a diastolic pressure over 100 is significant of trouble,
and over 110 is a menace.


FACTORS INCREASING THE BLOOD PRESSURE

With normal heart and arteries, exertion and exercise should
increase the systolic pressure, and generally somewhat increase the