s be considered as a subordinate division | 
similar virtues, being used principally to 
and ee nly in not produ- 
and diminished action, which — 
might be supposed owing 
seems also to be some- 
10Fr¢ o such effect in any dose, 
‘since, although they are so much inferior to narcotics in this, 
respect, they are equally powerful in repressing inordinate and ir- 
regular muscular action. This difference may be explained, on the 
supposition that they are equally powerful stimulants, but are less” 
_ diffusible, and more durable in their action, or that they are powerful 
diffusible stimulants, possessing little direct power of diminishing the 
excitable principle. Considered in this point of view, they will form 
n int sdiate class between narcotics and tonics ; and experience — 
they partake of the properties of both ; several narcotics — 
[tonics being frequently used as antispasmodics. pasha 
_ From the name given 10 this class, their effects may be easily un- — 
derstood. Spasm is an irregular contraction of a muscle; some-— 
times the contraction is permanent, at other times it alternates with © 
relaxation, but is still irregular. Such medicines as obviate and re- 
move such affections, are termed antispasmodics. eT a 
-- Spasm may arise from various causes. One of the most fre- 2 
quent, is a strong irritation continually applied; such as dentition — 
or worms. In these cases, narcotics prove useful, by diminishing 
irritability and sensibility. Sometimes Spasm arises from mere de- 
_ bility; and the obvious‘means’of removing this is by the use of 
tonics. Both narcotics and tonics, therefore, are occasionally usel 
‘as antispasmodics, such as opium, camphor, and ether, in the one 
elass, and iron, calomel, and*Peruvian bark, in the other But 
there are farther, several substances which cannot be with propriety 
referred to either of these classes, and to these the title of antispas 
biodics may be more exclusively appropriated. Sede: 
"1. 
CLASS III.—TONICS, 
__ By tonics, are understood those substances whose ; 
fion is to give strength to the system. Their operation is not me 
“cManical, as was once conceived ; they act not on the simple sole: 
increasing their tenson or tone, but on the living fibre, and merely 
powerful stimulants, permanent in their operation. yer 
ven im excess, are used unnecessarily, or for too long ime,” 
they excite 
* 
