the living body. We observe this in the case of all contagions, particularly in those we call specific contagions, and, so far as my observation goes, even in those that are not strictly specific; when we can trace a disease, we can in some measure fix its species. Thus, in the case of small-pox, a great many varieties have been marked, but they are varieties only of one species, a proof of which is that from the same contagion-that is, from the same seed-all the essential circumstances are produced.

This reference to germs as a specific contagion is the first that had occurred in all medical literature previous to Cullen, except by inference in the works of Hippocrates, as the foundation of his Humoral Pathology, and the necessity of elimination in certain diseases. Hippocrates, and Galen his disciple, saw that in continued fevers

especially of the ataxic and toxic type-the blood was infected and became putrid-as in putrid typhus, very prevalent in their time, and later in all malignant diseases.

But to proceed: Inoculation for variola was in vogue in Cullen's day, as it was found to modify the severity of the malady, as a rule, when it did not prevent it altogether, and to render an inoculated subject immune against subsequent attacks of the disease.

This is the solid foundation of inoculation [says Cullen], that we have now learned to modify the body in such a manner that the contagion when applied will not give rise to these varieties and anomalies. I shall

add here [he continues] what I think a curious corollary, namely, that the specific nature of the contagion and the dependence of the variety of the disease upon the nature of the body are presumptions in favor of all specific contagions. When we shall have acquired some more experience [he wisely says] with the manner of fitting the body, and of conducting the inoculation in the disease as we do now in smallpox, I am persuaded that the practice will be equally appreciable.'

I

These words, be it observed, were written half a century before the discovery of the process of vaccination by the English country doctor, Jenner, more than one hundred years before the establishment of the Pasteur Institute at Paris, and the discovery of Immune Medicine by Pasteur and Loeffler, which fulfils the great need pointed out, in a manner truly prophetic, by the sage of Edinburgh, about the year 1760.

Cullen's "First Lines of the Practice of Physic" is his most notable work, and the one by which he will be best known to posterity. Many of his procedures in practice have been superseded by the advance of knowledge, both as to the causation of disease and the improvements and extensions of Pharmacy and Materia Medica, of course; but the work could be used with profit to-day by students of medicine. Not so much could be said of his works on Nosology and Materia Medica; but these were far in advance of his time Nosology and Physiology, p. 252.

and add lustre to the posthumous fame of their great author.

We think the reader will agree with us, from the foregoing citations from Cullen's writings, that he was a profound thinker, and possessed unusual powers of logical induction in matters within the domain of the demonstrable. When he entered another sphere-into the vale of mystery, we were going to say,-he flounders about like his distinguished predecessors. He throws no light upon the nature of Life nor of the human Personality, nor of the Yux of Aristotle, which it is demonstrable exists in the body corporeal. "I think, ergo I am," is sufficient demonstration of a fact as fixed in the mental substratum of things as the rocks and the everlasting hills are in the earth.

It is a strange phenomenon that in reasoning upon the facts of life and mind men will leave the inductive method, with which the great structure of Science has been reared, and take to speculation, the hypothetical, when, in truth, they ought to adhere to their method; observe, experiment, pile up data; then reason from the generals to particulars and accept the induction. This will not lead one behind the veil of things, but it will conduct one to the fount whence all things proceed, as far as we can go, or have a right to go, or that it is profitable to inquire. It is doubtful if man possesses any faculties that will ever enable him to inquire into the nature of Final Causes.

FIFTH: PERIOD OF THE RENAISSANCE

(Continued)

CHAPTER VIII

MEDICINE IN THE EIGHTEENTH CENTURY
(Continued)

As

S one scans the progress of medicine during the last two centuries he cannot fail to have perceived an undercurrent of development along lines of inductive science, that has been unbroken in its flow. Now and then a remarkable genius has arisen and sought the attention of the medical student with hypotheses fanciful and fantastic, just enough to awaken a livelier interest in the occult and abstruse with which medicine must always be identified, and has succeeded for a while in confusing the minds of men as to the verities of practice; nevertheless, the confusion has been temporary, like the mists of a morning which have soon passed away and left the medical atmosphere clearer and more whole

some.

An instance of this kind may be observed in the irruption of John Brown at Edinburgh in the year 1735. Brown hardly deserves to be taken seriously in connection with scientific medicine,

and but for the furore which he created in the medical world we should pass him by with a single paragraph. He was born in poverty, the son of humble parents. In some way he managed to acquire a primary education, and ultimately became secretary to the illustrious Cullen at the University of Edinburgh, and was finally advanced to a Chair in that celebrated institution. He was a man of genius of a certain type, of push and cheek, of quick wit and sharp repartee, and made his way to prominence by a show of learning which he did not possess. But he attracted attention and acquired a following in Edinburgh, Germany, and Italy also; and having quarrelled with his former preceptor, Cullen, he boldly advanced a new hypothesis of the theory and practice of medicine, in opposition to his great master. The hypothesis as explained and exploited by himself was simple and brought all the great problems of therapeutics, the nature of malady, and the modus operandi of medical agents within the reach of minds the most simple.

Brown-the author of what was called in its brief day the "Brounonian System of Medicine" -built his system on Haller's physiology, and his discovery that irritability and contractility had some relation to vital phenomena. Brown conceived that irritability and non-irritability, excitation and non-excitation, could be used in explaining the nature and causation of disease and the adaptation of medicines to cure it.