8
"It (the materia medica) includes two distinct departments, viz:
First, Materia  Medica proper, embracing simply an account of the
history and properties, physical and chemical, of medicinal agents,
and of their effects on the system in health. Second, Therapeutics,
that which relates to the effects of these agents in their applications
to the managemant of disease."-(Beck.)
Although Dr. Beck includes the physical and chemical properties,
and the natural history of medicines, in the materia medica proper,
they are excluded from the present inquiry as plainly belonging to
other branches. It would seem that this limitation of the science
must ere long receive the assent of all men. It is certainly proper
to limit the subject of investigation as definitely as possible. If,
however, the distinctions above stated are observed, it is comparatively unimportant whether the subjects are avowedly considered
as separate sciences, or are held as branches of one science. But it
is essential to exact inquiry, that their inductions be kept apart.
An ambiguity exists in the word medicine, according as it is
taken in its relations to science or to use. In therapeutics, a medicine is a substance used for the cure or mitigation of disease. In
the materia medica, considered as an independent science, it is a
substance which has certain powers and properties which make it
likely to be thus useful, even though it may never have been applied to actual use. The ambiguity is avoided by some, by using
the term drug to designate an agent known to have medicinal properties without regard to therapeutic applications. There is no way
of avoiding the difficulty in regard to the meaning of the terms
employed, that is entirely free from objection. It is necessary to
use them as scientific terms, in order to bring the subject within the
rangs of logical investigation. And if it is necessary to use one
term in two senses, we should be careful not to base arguments on
one signification which apply only to the other.
The materia medica has complex relations. In common with
some other physical sciences, it has not always been based exclusively upon a rigid observation of natural phenomena. A stage of
crude deductions from imperfect data seems necessary as a preparatory process. Even now the effort is a common one, to deduce the
properties of medicines by processes of reasoning. And doubtless
it is destined to continue as a deductive science, as well as an inductive one. It also has relations to the other medical branches.
Induction, though not usually the first to attract attention, is the



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The application of these principles has difficulties and is subject to some modifications in the different sciences, according to
the nature of the subjects of inquiry. But it is found in each of
them, that whenever a way is opened, by which a more strict
adherence to these principles is secured, corresponding advancement in the science results.
If a scientific materia medica now exists, it must be in accord
with these principles. If such a science is yet to be built up, it
must be by conforming, as strictly as is possible in the circumstances, to that philosophy which has done so much for other branches
of knowledge. The relation between principles on the one side
and investigation on the other is a fixed one. Whenever a subject can be mentally separated from other topics, all questions in
regard to it are to be referred, singly and as directly as possible,
to the observation of natural phenomena.
To apply the principles heretofore appealed to, to the development and to the study of the materia medica, the following things
must be done.
1. The subject must be placed on a scientific basis. In other
words the investigation must be restricted within definite limits.
2. The phenomena obtainable by observation and experiment
must be determined.
3. The phenomena thus obtained must be compared and classified in their natural relations, considering the end in view.
When these things are done, the application of the knowledge
thus obtained, to the other branches of medicine, will deductively
open new channels of investigation, by which the materia medica
can be further developed.
1. To bring any investigation into accord with the demands of
science, it is essential that the steps be taken within certain well
defined limits. These limitations will be considered under the
following heads. The development and the study of the science
must be by processes which are (1) inductive; (2) separate; (3)
without regard to practical utility; and (4) definite.
(1.) It is to be borne in mind that induction is the essential
part of the process and that it must be as direct as is possible.
Nothing must be omitted that will add to the accuracy, to the
completeness and to the availability of the inductions. Nothing
must be admitted as a substitute for them. There are other things
necessary to complete success, but in each of them deficiencies may



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arrive at the truth. From the want of these precautions many
errors have been handed down from writer to writer for many
years; and even at the present time there are medicines which
have been long in use, upon the precise virtues of which opinion
is yet unsettled."
Prof. Alfred Stille-(op. cit., vol. 1, p. 32) has the following
passage.
"The uniform action of a medicine upon healthy structure or
function is its physiological operation; its curative action or function is called its therapeutical operation. To determine the former
is comparatively easy, for as compared with the abnormal, the
normal action of the system may be viewed as constant and uniform.
But the latter involves infinite difficulty, for we are required to
determine the influence of an agent upon functional and structural
conditions, with the natural termination and tendencies, of which
we are only imperfectly or not at all acquainted. Whatever else
they may do, experiments upon the healthy organism can never
fully reveal the manner in which medicines cure disease, because in
the latter case an element is involved which does not exist in the
former. But if we are ever to acquire a distinct idea of the curative operation of medicines, that is, of their operation upon the
tissues, organs and functions when they have departed from their
normal condition, we must possess a standard with which to compare the effects that medicines produce; and however imperfect it
may be, no other standard is available than the operation of the
same medicines upon the healthy economy."
John Stuart Miill-(Logic, p. 266, New York ed.), has the
following.  "Besides natural pathological facts we can produce
pathological facts artificially; we can try experiments even in the
popular sense of the term, by subjecting the living being to some
external agent. As this experimentation is not intended to obtain
a direct solution of any practical question, but to discover general
laws from which afterwards the conditions of any particular effect
may be obtained by deduction; the best cases to select are those
of which the circumstances can be best ascertained; and such are
generally not those in which there is any practical object in view.
The experiments are best tried, not in a state of disease, which is
essentially a changeable, but in a condition of health, comparatively
a fixed state. In the one, unusual agencies are at work, the results
of which we have no means of predicting; in the other, the course
of the accustomed physiological phenomena would, it may gener3