sailed" with small-pox; of a city "assaulted" with cholera, and of its inhabitants being decimated by the "stealthy ravages" of consumption. Now, so considered, there is no such thing as disease. Who has ever seen it isolated from the body?—And when, in accordance with this view, we ask the question, "What is disease?" there is but one answer, namely: Disease is the tertiary product of two factors: 1. Of impressions or stimuli acting upon the body from without; and, 2. Of the reactions performed by the organism in response to the impression of such stimuli. The tertium quid following the action without, and the reaction within, is the thing "disease." Exactly in the same manner a stone thrown against a pane of glass makes a hole in it; yet, when we try to consider the hole as a separately-existing entity, we find it does not so exist. If it did, we might take away the pane of glass, and leave the hole by itself, but this is impossible. The aperture in the glass is a tertium quid resulting from two factors, viz., 1. The action of the stone from without; and, 2. The reaction of the glass when struck by the projected missile. Furthermore, it is evident that the quality of the resulting tertiary product can be made to vary indefinitely, either by varying the character of the action (i, e., by modifying the shape, size, direction, velocity, etc., of the stone), or by altering the reactive properties of the glass (i. e., by modifying its thickness, elasticity, inclination, etc.). Equally so the quality of disease will vary in different individuals in accordance with the variation in the quality of their reactive powers, as well as in conformity with the character of the actions by which the reactions are elicited.
Now, since the external stimuli which act upon the body in the manner we have described only produce their effect in living organisms (for in dead bodies and inorganic matter they do not elicit similar reactions), it is evident that the tertiary products which we call organic disease are purely the result of vital processes, and for this reason alone must be conservative, as are all the phenomena of life. Once dispute this and we should have to adopt the other alternative, that the organism would be better off if the reactive powers with which we find it to be endowed were annulled; and this conclusion would compel us to acknowledge the possibility of our thinking out an improvement upon Nature—a monstrous assumption, which no student of science will for a moment entertain.
In a condition of health the various processes going on in the body, which we call vital phenomena, are nothing more than a series of internal reactions provoked and maintained in obedience to the impression of surrounding conditions that act upon the organism from without. The reactive powers possessed by the healthy organism are perfectly natural to it, and, so long as the external stimuli impressing the body from without are also perfectly natural, the resulting tertium quid will simply consist of a naturally-constructed, a physiologically-developed organism. And if we now ask ourselves, "What is the use or design
