The work which has been described under this section is of interest
as indicating the newer experimental work on the physiology of blood
pressure. Much of it is new, however, and it is difficult to draw
absolute therapeutic conclusions from the evidence offered.


THE EFFECT OF DRUGS ON BLOOD PRESSURE

Free catharsis is a well established and valuable method of
relieving the heart in many cases of broken compensation, and in
cases with high blood pressure even while compensation is still
good, salines administered once or twice a week assist in
elimination, and in the reduction of blood pressure.

However, profuse purging in heart disease may be followed by
unfavorable symptoms, especially when the systolic blood pressure is
low. When there is hypotension, or when the diastolic pressure is
high and the venous pressure is high, and when there is edema or
effusion, watery catharsis should be caused only after due
consideration, and always with a careful watching of the effect on
the heart and blood pressure. The blood pressure is lowered by such
catharsis, and the heart is often slowed. Neilson and Hyland
[Footnote: Neilson, C. H., and Hyland, R. F.: The Effect of Strong
Purging on Blood Pressure and the Heart, THE JOURNAL A. M. A., Feb.
8, 1913, p. 436.] studied the effect of purging on the heart and
blood pressure, and were inclined to the view that in serious heart
conditions brisk purging should not be done. They think that the
slowing of the heart after such purging may be, due to an increased
viscosity of the blood, or perhaps to a reflex irritation from the