191 [REF. 
force and resisting power every where in nature: 
and Cullen’s intrenchment of the modus operandi of 
refrigerants behind the application of this antizy- 
mic power as he terms if, to the exhibition of neu- 
tral salts to the stomach ;—after devoting ina word 
as much reflection to this intricate subject aS its — 
complexities required: and bringing to my aid:what 
practical experience my opportunities have in 
near twenty years afforded me, of the operative 
phenomena of medicines on the body—I am not 
able to perceive the slightest shadow of reason for 
allowing the existence of any such remedies as in- 
ternal refrigerants. Consequently I enjoin an ob-- 
literation from your minds, of the misleading prac- 
tice to which the admission that there are such, tends, 
when you pass in review the multitudinous subjects 
of Materia Medica. I shall enter more into de- 
tail on this point, in the lectures ; in the mean 
while I wish to be understood, that I not only ad- . 
mit of such a set of remedies and agents of thera- 
peutic power, as may~ be grouped under the title 
of topical external refrigerants, but I believe such 
yemedies could find no suitable place under any 
other name. And hence though unfriendly to 
classification, purely as such, yet I believe that 
method of the mind which groups by a catch-word, 
(if I may resort to the stage for a figure) an assem- 
blage of articles producing a singleness of effect, 
and an undeviating fidelity in its production when 
applied under the saine circumstances—may be 
useful ina practical point of view. Such a group 
I belicve topical refrigerants to be, and they are 
the more-constant in their operation and consistent 
in their effects, because they are influenced by 
chemical and physical principles. It will be per- 
ecived that in the second volume of these outlines I 
sometimes speak under medical property and uses’? 
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