recisely the reverse of this doctrine was likewise advanc € 
their exciting effects were those which appeared first, and we 
ceeded by those of debility, and as the first were produced from a_ 
small dose, while the others were occasioned when the dose was _ 
comparatively large, these substances were regarded as direct stimus __ 
lants, capable of exciting the actions of the system; and the symp- __ 
toms of debility which they so frequently produced, were considere 
as_arising from that exhaustion of power, which, according 
general law of the system, always follows increased action suc iy. 
raised and not kept up. ‘T'hey were regarded, therefore, as directly 
stimulant, and indirectly sedative, and the peculiarities of their ac- 
“tion were ascribed to their rapid and transient stimulant opera' on. 
If, in investigating this subject, we merel: ' contrast these two 
theories, little doubt ean remain of the superiority of the latter. The 
suppositions of there being a power in the living system, fitted to 
resist any noxious agent, and of such a power acting before the dele- 
terious effects have taken place, and thus retarding or preventing 
their production, are improbable, and unsupported by any satisfac- 
tory proof. Since the stimulant operation of narcotics always pre- - 
cedes the symptoms of languor and debility which they produce; it 
is the direct conclusion, that these latter are the consequences of 
the former. The analogy between narcotics and other substances, 
admitted to be stimulants, but which are less rapid in their ope 
* 
is also in many respects so direct, as to prove similarity of on. 
And their utility in several diseases, in which they are employed as 
stimulants, is scarcely consistent with the opinion, that they possess 
a real depressing power. Some doubt, however, is still attached to 
the theory that they are direct stimulants, from the fact, undoubtedly 
true, that the sedative effects of narcotics are frequently dispro- 
portioned to their previous stimulant operation, allowing even in 
such cases, for its rapidity and little permanence; and the propo- 
sition, though apparently somewhat parodoxical, is perhaps just, that 
these substances are at once capable of stimulating the living fibre, 
and, independent-of that stimulant operation, exhaust to a greater 
or less extent, by direct operation, the living power. ‘The effects 
of certain chemical agents on the living system, as lately ascertained, 
appear to support some conclusion of this kind. - ; 
Narcotics being capable of producing either stimulant or sedative 
effects, may be practically employed with very different intentions. 
Either operation is obtained chiefly by certain modes of administra- 
tion. If given in small doses, frequently repeated, the actions of 
the system are excited, and kept up. But if given in larger doses, 
lessened 
at distant intervals, the state of diminished action and le 
sensiblity is obtained. As stimulants, they are employed in various 
diseases of debility : in intermittent fever, and continued fevers of 
the typhoid type; in gout, hysteria, é&c. As sedatives, they are 
used to allay pain and irritation, to procure sleep, and diminish secre- 
_ fons; hence their applications in spasmodic and painful diseases, 
_ 4m heemorrhagies and increased discharges. In an inflammatory — 
State of the system, the use of some of them is not altogether without 
nger from their stimulating effects. oe: - 
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