_ EXTERNAL APPLICATION OF ACONITE. 59 
forming a thick compound with part of the lard, which renders it 
difficult to make a proper ointment. 
The proportion of the alcaloid in this prescription will, in general, 
be sufficient to begin with, but it may be augmented to four or five 
grains to the drachm, if necessary ; and in one case of Tic-Douloureux 
of unusual severity, as much as eight grains to the drachm were 
prescribed with the most marked benefit. The best manner of 
applying the ointment, is simply to rub a small part of it over the 
whole seat of the affection, till the pain be either for the time re- 
moved, or until the full effect upon the cutaneous nerves above 
described be brought about; and the friction should be repeated 
three or four times, or more frequently in the day, according to the 
effect produced upon the disease. The proportion of the Aconitine 
ought to be increased at every second or third friction; and the 
same rule elsewhere laid down, in regard to the action of Veratria 
and Delphinia, also holds good in the present instance,—namely, 
that unless the friction occasion a full development of the peculiar 
impressions caused by the Aconitine when rubbed on the skin, no 
benefit whatever is to be looked for from its employment. It is 
almost needless to remark, that an application of such activity should 
not be resorted to, if there be the slightest abrasion of the surface 
of the skin, and that it should be carefully kept from coming in 
contact with any of the mucous membranes. 
External Application of the Ammoniated Extract of Aconite, &c. 
Tur next preparation that requires notice, is the ammoniated 
extract of Aconite; this is probably the best appellation for the sub- 
stance, although it bein reality a mixture of all the active principles, 
along with extractive and other matters. It is made by evaporating 
_ very carefully, and at a low temperature, the tincture of the dried 
root of the plant, prepared as already directed in the process for 
obtaining the Aconitine, to the consistence of an extract. To every. 
drachm of this, eight or ten drops of liquor ammoniz should be added ; 
and after the mixture has stood a short time in a very gentle heat, 
to drive off the excess of ammonia, it is to be used in the form of oint- 
ment, according to the following prescription :— 
hk. Extract. Aconit. Ammon. 4 i. 
Axung, 3 iil. M. ut fiat unguent. 
This, from its dark colour, may be a less agreeable application 
than the Aconitine ointment: but it appears to me, to be at least as 
efficacious, and it has the advantage of being easily and cheaply 
prepared: and on these accounts it is better suited for hospital 
yractice. The proportion of the extract may be increased two or 
three-fold, according to circumstances. sip. 
When this ointment is rubbed upon the skin, it occasions sensa- 
tions in the part, similar to those which are produced by the Aco- 
nitine ointment; they are, however, rather more pungent in their 
