310 
ON THERAPEUTICS. 
tive agency in bloodletting, which may fairly claim to have 
the property of diminishing action without occasioning 
any previous excitement at all allied to the action of a narcotic 
drug. In accepting the classification, we may premise that 
the term sedative shall be restricted to those agents which 
least resemble narcotics in their primary effects, and again 
that a further qualification is necessary, referring to the 
dose of the agent selected. The difference in the effects of 
the same drug in different doses, and under various methods 
of exhibition, has already been insisted upon; it is not there¬ 
fore unreasonable to require that the term sedative shall be 
absolutely restricted to those doses, and those methods of ad¬ 
ministration, which are found to result in the most direct 
depression to the avoidance of any primary excitation. Seda¬ 
tive action, we may also observe, properly excludes that 
peculiar stupefying effect which is one of the most decided 
indications of narcotic action. 
The agencies which are capable of inducing this direct de¬ 
pression are not numerous—they comprise bloodletting as the 
most decided, and the drugs, hydrocyanic acid, digitalis, and 
aconite; the selection of either of these means will be regu¬ 
lated by a number of circumstances, but it is understood that 
either or all may be applied to the treatment of those derange¬ 
ments in which the principal elements are excited—nervous 
and vascular action. The use of sedatives in cases where 
no inflammation is present, or even threatened, merely for 
the purpose of allaying pain, or decreasing muscular action, 
is to a certain extent a diversion of them from their legitimate 
object; undoubtedly they act as anodynes, and also as anti- 
spasmodics, but these actions are developed in a more eminent 
degree by the true narcotic medicines, which are always 
equally available. 
Sedative action is, under ordinary circumstances, only 
preferable to narcotic action when the exalted nervous and 
vascular functions do not arise from any local irritation or 
pain, but from a general and diffused excitement or morbid 
sensibility that cannot be referred to any particular part of 
the organism, but which is always associated with some degree 
of inflammatory action. In such instances, it may sometimes 
be a question whether the most direct advantage would 
follow from the operation of an agent upon the nervous 
system, and indirectly upon the circulating organs, or from 
the direct influence of the sedative upon the heart, leading 
to an immediate cessation of its excessive action. In many 
cases the principal apprehension arises from a continuance 
of the excited action of the heart forcing blood into an organ 
