ON VESICATING APPLICATIONS. 
307 
combination. The Emplastrum Epispasticum of the London 
Pharmacopoeia of 166S, contained no less than fourteen ingre- 
dients, among which were mustard, euphorbium, long pepper, 
stavesacre, pyrethrium, cantharides, gum ammoniacum gal- 
banum, bdellium, and sagapenum, with turpentine, resin, &c. 
The greater part of these ingredients, however, have long 
been discarded in applications of this description; and, although 
the Edinburg College still order turpentine burgundy pitch, 
acetate of copper, mustard seeds, and black pepper,jin addition 
to the Cantharides, in their Emplastrum Cantharidis Composi- 
tum, the advantage of such heterogeneous mixtures may be 
doubted. Indeed, the remark of Dr. A. T. Thomson with 
regard to this latter preparation, that "its operation is accom- 
panied with very great pain, and a pungent sense of heat," 
and "is apt to cause very unpleasant ulceration if allowed to 
remain too long applied," would seem to sufficiently indicate 
the propriety of finding a substitute for so violent a remedy. 
Messrs. Pugh and Plews, of Edinburgh, several years ago, 
introduced a preparation, under the name of Chemical Blister- 
ing Fluid, which they recommended as a substitute for the 
common blistering plasters. They describe it as producing 
its full effect in three hours, and say, "it is found also that the 
burning heat, great thirst, general irritation, strangury, and 
other unpleasant effects, so frequently attendant upon the 
application of the old blistering plaster, are avoided by the use 
of the Chemical Blistering Fluid. It is not only easier and 
cleanlier in its application, milder, and more efficacious in its 
action, than the fly blister, but the skin, after its use, is much 
more easily healed; and it may be reduced in strength so as to 
render it applicable to the tender skin of infants, which the 
old blister cannot be." 
This preparation appears to be similar to the Acetum Can- 
tharidis of our last Pharmacopoeia, which is described by Dr. 
A. T. Thomson, as intended "for raising a sudden blister." 
The formula of the London College is, two ounces of powdered 
Cantharides to one pint of acetic acid, macerated for eight 
days and strained. It is generally directed to be used, by 
