DR. PROUT ON CHEMISTRY. 453 
gist, and by multiplying uncertainties, serve only to contribute to 
error. 
Imperfect, however, as this department of chemistry is, and 
always must be, it is yet capable, when judiciously applied, of 
contributing much valuable information to physiology and patho¬ 
logy. Great care and experience, however, are necessary on the 
part of the operator, which alone will give that tact and power of 
discrimination calculated to enable him to disentangle the intri¬ 
cacies presented to him, and to seize the clue that will lead him 
to truth. By its aid, for example, the physiologist can often 
identify the most delicate and refined organic products in a way 
that cannot be done by any other means, and thus be enabled to 
detect minute variations from the healthy standard, often of the 
utmost importance in a physiological and pathological point of 
view. Another field of inquiry in which this department of che¬ 
mistry can be usefully applied is, the study of the effects pro¬ 
duced by medicinal agents. Many of these, as is well known, 
often change or modify organic products, and particularly secre¬ 
tions, in a remarkable manner; and when the nature of these 
changes is understood, they often lead to the most valuable prac¬ 
tical inferences with respect to the periods and modes of adminis¬ 
tering particular remedies. In short, the physiologist, in a great 
many instances, by the aid of chemistry, can so associate the 
evanescent and fleeting phenomena of life and of disease with the 
more tangible and intelligible phenomena of matter, as not only 
to be enabled to form a more just notion of their nature himself, 
but to convey it to others; and thus, instead of being obliged to 
permit the greater part of his knowledge to die with him, to hand 
it down, in an intelligible form, for the benefit of posterity. 
Thus, then (to recapitulate briefly what has been said), we 
may consider chemistry to hold a sort of intermediate rank be¬ 
tween anatomy on the one hand, and metaphysics or psychology 
on the other; and by gradually coalescing with both, to connect 
the whole, as it were, into one great system. Of these extensive 
branches of knowledge, anatomy, from its obvious and mechani¬ 
cal nature, no less than from the great attention that has been 
bestowed upon it, is by far the best understood, and scarcely a 
nerve or fibre, perhaps, remains that has not been again and again 
demonstrated, so that comparatively little remains to be done in 
it. On the other hand, if we know little of the nature of living 
action or psychology, it has not been for w T ant of inclination and 
attempts to investigate it, but simply from the nature of the sub¬ 
ject, which, for the most part, is beyond our comprehension. 
While, if we turn to the vast and intermediate field where, by in- 
VOL. IV. 3 Q 
