380 
ON THERAPEUTICS. 
cases where sloughing has commenced after firing, we have 
observed the benefit that has followed the persistent use of a 
dessicating powder of alum and Armenian bole; in many 
cases the unhealthy condition has ceased, and much of the 
surface which we considered hopelessly loosened has partici¬ 
pated in the general restoration. 
As a simple method of arresting haemorrhage from small 
vessels, astringents are valuable; when the application of 
cold has not sufficed to prevent the flow of blood, the 
powder of matico, or the leaf, applied with the under side to 
the bleeding surface, at once stays the oozing ; it is even 
asserted that bleeding from large vessels may be thus ar¬ 
rested. 
The common resort, however, to powerful astringents in 
every case of simple diarrhoea is to be reprehended as un¬ 
necessary, when mild alkalies will be more effective and more 
safe. Astringents, from their potency, are only justifiably 
employed when excessive evacuation threatens extreme con¬ 
sequences, and even then they are only to be exhibited with 
caution. 
THERAPEUTIC ACTION OF THE THIRD GROUP. 
The power of inducing some molecular change in the con¬ 
stituents of the animal body probably belongs, in a greater 
or less degree, to all medicinal substances ; but the obvious 
indication of such change is seen in only a few instances. In 
the course of diseased action these molecular changes are 
frequently very marked, both in the solids and fluids of the 
body; structures and functions are so entirely altered as to 
lose their ordinary characteristics. The term 4 *' perversion” 
is applied by the pathologist to express the occurrence of 
such derangements. 
In the course of medicinal action we observe instances of 
such marked change of structure and function, that the use 
of the same word may, without any qualification, be admitted. 
The agents which produce these peculiar effects belong to 
three distinct divisions—antacids, caustics, antiseptics. 
Antacids physiologically alter acid secretion, and render 
them neutral or alkaline. 
Caustics produce even more definite changes, destroying 
the vitality of the textures and forming new combinations. 
Antiseptics modify the products of decomposition, destroy¬ 
ing fetor by causing new compounds to arise from the union of 
some of their constituents with the elements of the secretions. 
