MATERIA MEDICA. 
vigour wlien debilitated by immediate dis- 
ease. They may be divided into stimu- 
lants, as various preparations of mercury, 
iron, zinc, and other metals ; and astrin- 
gents, as chamomile-flowers, myrrh, Peru- 
vian, and other barks, and gentian. It is 
hence obvious, that this class of medicines 
has a near relation to those noticed in the 
class that immediately precedes, and imme- 
diately follows it. On which account we 
shall dismiss it with a single additional ob- 
servation or two. The changes induced in 
the system by the use of tonics are, increase 
of muscular power, greater moderation, 
and a firmer stroke of the pulse, increased 
desire for food, and an augmented vivacity 
of the animal spirits. Hence their use is 
clearly indicated in all cases in which there 
is a deficiency of these natural powers or 
desires. They are therefore contra-indi- 
cated by the existence of a plethoric habit, 
constitutional predisposition to maniacal af- 
fections, or topical hmmorrhage, and a san- 
guineous temperament. 
13. Of Stimulants. 
These, like the last, are medicines which 
have a power of exciting the animal ener- 
gy ; but for the most part topically, rather 
than generally, or for a shorter period of 
time. They occasion a particular sensation 
referred to the part more immediately act- 
ed upon ; frequently a sense of pain ; they 
increase the action of muscular fibres in that 
part, particularly in its vessels ; they in- 
crease the enei'gy of the sensorium ; they 
increase the nervous energy in the moving 
fibres through the system in general. Tlie 
changes induced in the system from the pri- 
mary effects of stimulants, are, acceleration 
of the motion of the blood in the part to 
which they are particularly applied ; an in- 
crease of the force of circulation in the sys- 
tem in general ; an increase of excitement 
in the powers of sensation ; and an aug- 
mentation of mobility and vigour iu the 
muscular organs. They may be divided in- 
to the following heads : topical, of which 
we have examples in mustard-seed, cantha- 
rides, mercurial i)reparations ; diffusible, of 
which we have instances in volatile alkali, 
electricity, heat ; cardiac, such as cin- 
namon, nutmegs, and other spices, and 
wine. 
The indications of cure which stimulants 
are capable of fulfilling, may be derived 
from tile three following sources : 1. From 
their affecting the state of circulation ; 
wUence they may be employed, to facili- 
tate the passage of blood through parts in 
which it is morbidly obstructed ; to aug- 
ment the force and celerity of the circula- 
tion, where it is morbidly slow and weak. 
2. From their acting on the powers of sen- 
sation: whence they may be employed, to 
quicken the senses where morbidly dull ; to 
rouze the mental faculties when in a lethar- 
gic state; to exhilarate a despondent con- 
dition. 3. From their acting on the mov- 
ing fibres : whence they may be employed, 
to restore the power of motion where mor- 
bidly deficient ; to increase the strength of 
motion where morbidly weak. Thfese indi- 
cations may be illustrated and confirmed 
from practical observations concerning the 
effects of this class of medicines, as employ- 
ed in cases of syncope, apoplexy, and palsy. 
The cautions to be observed in employing 
stimulants, are, the pain they excite, the 
violence of circulation, or the flow of the 
animal .spirits which they produce, the mo- 
bility of tire system which arises from their 
employment, and the collapse, which is the 
consequence of high and sudden excite- 
ment. The conditions of the system, which 
chiefly require attention in their employ- 
ment, are delicate and irritable habits. The 
circumstances chiefly to be attended to, in 
the regimen necessary, respect the diet 
and temperature best adapted to the stimu- 
lant employed, and the nature of the parti- 
cular disease in which it is used. The indi- 
viduals belonging to tliis class are chiefly 
contra-indicated by the presence of the fol- 
lowing morbid states: a high degree of mor- 
bid irritability ; the circulation uncom- 
monly accelerated ; and a preternatural dis- 
position to hEemorrhage. 
14. Of Antispasmodics. 
By these are meant whatever has a power 
of allaying inordinate motions in the sys- 
tem, particularly those involuntary contrac- 
tions which take place in muscles naturally 
subject to the command of the will ; they 
counteract and remove various causes excit- 
ing contractions ; they diminish the influence 
of the nervous energy in the parts spasmo- 
dically affected. The changes induced in 
the system, from the primary effects of an- 
tispasmodics, are, the restoration of the 
proper balance of the nervous energy in dif- 
ferent parts of the body, the restoration of 
the due influence of the will, and the resto- 
ration of the natural state of tension to the 
muscles. The different articles referred to 
the class of antispasmodics may be distri- 
buted into the two following orders : sti- 
W 2 
