222 
LAURUS CAMPHORA. 
resis: in larger doses it allays irritation and spasm, abates pain, and 
induces sleep. The proper dose of camphor seems to be somewhat 
undefined at present; in this country it has been rarely given to the 
extent of Bi. In immoderate doses it has been found to produce 
vomiting, vertigo, delirium, convulsions, and other deleterious effects. 
Dr. Cullen, however, notices a case of mania under the care of Mr* 
Latta, surgeon, in which the dose of camphor was gradually increased 
to above sixty grains three limes a day, without any untoward 
effects, and by which the cure was effected. Dr. Heberden relates 
two instances in which camphor seemed to occasion stranguary ; Dr. 
Cullen considers these accidental occurrences, and says he has 
employed it fifty times, even in large doses, without ever observing 
its having any effect upon the urinary passages." We shall now 
quote what Dr. Cullen says on the subject of the dose of this sub- 
stance. " It may be given in doses of very different quantities ; and 
It appears to me from many trials, that doses of a few grains 
repeated only after long intervals, have hardly any effect at all, and 
that to obtain sensible effects from it, it must either be given in'laige 
doses, not under that of twenty grains, or, if given in smull dose'L, 
these must be repeated frequently after short intervals. To what 
length in either way we may proceed I have not experience enough 
to determine with any precision. From the effects of two scrupfes 
given in one dose, (in a case narrated) and in another quoted from 
Dr. Hoffmann, it would appear that such doses are violent and dan- 
gerous, but from some other experiments it appears that larger doses 
have been sometimes given with impunity ; and when it is given in 
divided doses, it appears from Collin's experiments, that it ''may be 
given to the quantity of a drachm, or two drachms in the course of 
a day; and in one of his experiments it was given to the quantity of 
half an ounce. It is probable that from large doses only consider- 
able effects are to be expected ; and as it appears that the effects of 
camphor are not very durable in the body, it will be obvious that the 
repeated and long continued use of it may be necessary to the cure 
of several diseases." We shall conclude this part, an important one, 
of our subject, by offering as an opinion of our own, that much 
depends on the state of the system at the time the medicine is ad- 
ministered ; the active properties of camphor evidently reside in the 
highly volatile oil which is one of its components, and where the 
capillary system is open, and a diaphoresis induced, by which this 
volatile substance is carried off, it is reasonable to conclude that 
the dose of camphor maybe pushed much farther than when the 
capillaries are closed, as in the dry hot state; of the skin which 
