IMPORTANCE OF THE STUDY OF CHEMISTRY. 
51 
organism as the chief constituents of the blood. These materials, prepared 
by vegetal life, the herbivorous animal receives and assimilates into its 
blood, to supply the constituents of its different organs and structures. 
Again, we have a series of substances, such as fat, sugar, gum, starch, 
&c., which, though not truly to be called nutriments, as having no part in 
the construction of the body, are no less essential to the maintenance of 
life. These substances serve the process of respiration; combining with the 
oxygen inspired by the animal, they continually compensate the loss of tem¬ 
perature, and thus become the source of animal heat. And here presents 
itself one of the most interesting subjects for contemplation,—the animal 
organism in its relation to the surrounding atmosphere. The full apprecia¬ 
tion of the effect of air and temperature on the animal system, was a most 
important step towards a true understanding of the conditions of health. A 
vast number of diseases originate in disturbances of the relation between 
the living system and these influences, the intimate knowledge of which 
affords to the physician the simplest, safest, and most efficient means of pre¬ 
serving health and of curing disease. 
Valuable as have been the fruits of chemical inquiry, still more may be 
expected from the further prosecution of this study. The notion that the 
action of most of our medicines is chemical, is daily growing into a general 
conviction. We admit that with every change wrought by pharmaceutical 
agents in the state of our organism, there occurs a corresponding change 
in its composition, resulting from their reaction on one or more of its con¬ 
stituents. But of these transformations, which doubtless could be expressed 
in numbers as definitely as can our laboratory-processes, how few are we in 
a condition to explain; in how few instances has the physician even a 
vague conception of the mode in which any medicine performs its office! 
Nobody doubts the power, which the principles of the Cinchona bark, or 
of tea and coffee, exert upon the living body, but we are perfectly in the 
dark as to the way in which they act upon the animal economy. But if we 
meet with a series of similar substances in several animal fluids; e.g ., urea, 
and creatine , almost constantly present in urine, glycocoll generally, and 
cystine , occasionally, excreted in the same liquid, and if we find that all these 
substances exhibit in their chemical relations a close analogy with quinine 
and theine, we begin to feel a sort of anticipation of the manner in which 
these agents may act upon the system. Such examples illustrate at once 
the nature of the aid which the therapeutics may confidently expect from 
the progress of organic chemistry. Medicine some years ago found itself 
in a predicament very similar to that of agriculture at the same period; its 
resources appeared to be in a state of exhaustion, the rich capital of facts 
accumulated in the department of organic morphology by the industry of 
the anatomist, and by the acumen of the physiologist, could not yield its 
full fruits until an equivalent of knowledge had been drawn from the study 
of bio-chemical phenomena. This state of things, however, is rapidly chang¬ 
ing ; associated with chemistry, medicine no longer draws the veil of vitality 
over processes, the mystery of which may be unlocked by the key of 
analysis; it no longer shrinks from climbing, step by step, the ladder of 
recognition, because its upper extremity, disappearing among the clouds, 
seems to rise for ever beyond the grasp of inquiry. The special zeal with 
which the field of organic chemistry has been cultivated during the last 
thirty years, the simple and accurate methods which we now possess for 
determining the composition of organic products, the amount of analysis 
actually performed, and, more than all, the still untiring energy of the 
numerous labourers in the same field of investigation, hold out the promise 
that the connexion between medicine and chemistry, becoming daily more 
intimate, will be productive of benefits, the importance of which we can 
scarcely venture to estimate in the present state of our knowledge. 
