DR. SEARLE ON THE USE AND OPERATION OF CALOMEL. 405 
subject, doubtless, as much so as the skin, to irritation and other 
local agencies operating upon its surface ; and thus, through its 
nervous sensibilities, also, may it be affected as well as other 
organs connected with it ; but neither calomel, rhubarb, jalap, 
wine, nor many of the numerous things administered as remedies 
do so affect it — not even ipecacuanha ; an infusion of which in- 
jected into a vein in the leg operates as an emetic in a quarter of 
the time required by any quantity administered by the stomach. 
These, then, when taken, are accordingly first absorbed into the 
blood, and each, during its circulation, severally operates in its 
own particular way — jalap as a purgative, ipecacuanha as an 
emetic — either directly upon the organ influenced, or indirectly so, 
by first influencing the brain and nervous connections of the part. 
In proof of this, the same remedies applied to a blistered surface, 
from which they become severally absorbed, in like manner 
operate as when taken into the stomach. 
Mercurials increase capillary excitement. — Calomel, when ab- 
sorbed by the veins from the stomach and bowels, in its passage 
with the blood through the liver, to which it is immediately con- 
veyed, excites this organ to increased secretive function ; hence 
the bilious evacuation which so constantly succeeds to the use of a 
grain or more. Proceeding from the liver, and admitted into the 
general current of the circulation, its operation I believe to be 
specific on the capillary system at large, exciting these vessels to 
increased action. Hence its general influence as a stimulant to 
the whole system, its renowned deobstruent power, and its opera- 
tion on the glandular system, increasing all the secretions. Its 
operation in exciting the capillary arteries, and thereby secretion, 
necessarily removes obstruction from the exhalent vessels, and 
congestion from their venous terminations — the cause of exuda- 
tion ; and thus is exudation prevented, and absorption at the same 
time increased ; and hence the accredited action of mercury upon 
the absorbents, in removing exudation of whatever kind, and the 
various dropsical affections. Its operation on the capillary system 
being general, the action of the heart, and that of the brain, 
through the medium of their organic structure, is excited also ; in 
short, all the functions. It thus operates probably by imparting 
qualities to the blood by which its constituent particles may have 
a greater affinity for oxygen — the vitalizing principle ; and thus 
may increased chemical action in the blood, and its consequence, 
excitement, take place throughout the system. But, whether this 
be the mode of its operation or not, the effect is, as I have described 
it, excitement to the general system. 
Indications which mercury fulfils. — The power of mercury in 
increasing capillary action is further evinced by the febrile com- 
vol. xx. 3 H 
