I take this opportunity of acknowledging. I have also made use of the "Principles of Medicine," by Dr. Williams, F.R.S., the late distinguished Professor of Medicine in University College, a work of great learning and merited reputation.

LONDON, JUNE, 1850.

PHYSICIAN AND PATIENT.

CHAPTER I.

UNCERTAINTY OF MEDICINE.

THE uncertainty of Medicine is a common topic in all circles, and yet it is one which is very generally misunderstood even by the intelligent and reflecting portion of the community.

They mistake as to the nature of this uncertainty, its causes, its practical influence in the treatment of disease, the means which should be resorted to in order to diminish it, and the best methods of guarding against the errors into which it is liable to lead us. These errors are, I may remark, so numerous, and so common, and interfere so constantly with the usefulness of the Physician, among high and low, educated and uneducated, almost equally, that the subject is one of vast practical importance. It is important not only to Physicians, but to the public, and to the public

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especially, for they are the sufferers from the multiform and often fatal injuries which these errors engender.

It will be profitable, then, to examine the different points to which I have alluded, so that it may be seen how far the science of medicine merits confidence, and by what tests an intelligent and thinking man may distinguish between that which rests upon substantial evidence, and that which is delusive.

That this is a distinction which often fails to be made by the shrewd and learned, as well as by the ignorant and unwary, the Physician has occasion daily to lament. The deductions of a rational and careful experience are continually confounded with the false assumptions and plausible fallacies of the mere pretender, and the fanciful vagaries of the enthusiast.

So far as my remarks will enable the reader to make the distinction to which I have referred, just so far will my object be accomplished.

When the Chemist mixes substances together, the composition of which he knows, he arrives at results which may be strictly denominated certain and invariable. If he be not able to do so at once, he can do so ultimately, by a series of experiments, varied to test each doubtful point. The results which he obtains are so exact that they can be expressed by numbers and definite proportions. The Physician can imitate the Chemist, it is true, in the application of tests in the investigation of disease, but it is necessarily a very humble and distant imitation; and no approach to the

certainty and definiteness of chemical analysis and synthesis can be expected in medical practice. When the Chemist mixes substances together, he knows what they are, and when he sees their effect upon each other, he has a right to expect the same effect to follow with absolute certainty, whenever he shall make the same mixture again. But the Physician cannot infer, from the effect of a remedy in one case, that the same result will certainly occur in another case which appears to be precisely similar; for he cannot know enough of the two cases to determine, beyond a doubt, that they are exactly alike. Age, sex, temperaments, habits, vital and other forces are brought into operation which essentially modify the effects of remedies.

If you suppose that the Chemist knows the nature of only a part of the substances which he puts into his retort, that the retort itself is made of materials which will act upon these substances, and be acted upon by them in return, and that, in the midst of this experiment, some foreign body gain admittance, producing an entire change in the process, the Chemist then resembles the Physician in the uncertainty of his results.

He will then, like the Physician, be obliged to make many experiments and observations to establish any one fact; and instead of drawing, as he now does, a well-defined line of separation between what is known and what is not known, he will, like the Phy

sician, have a middle ground of probability and supposition.

The causes which tend to make disease complicated, and prevent uniformity in the effects of remedies are principally these, viz.:

1. The sympathy existing between the different organs of the body.

2. The influence of unseen causes or agents (vital forces).

3. Natural changes, arising from the tendency which exists in the system to throw off disease, appropriately called the Vis Medicatrix Naturæ, or restoring power of nature; and, in connexion with this, the tendency to a definite limit, manifest in some diseases; as, measles, small-pox, and scarlet fever.

4. Mental influences.

5. Idiosyncracies, or individual peculiarities.

We will examine, in a familiar way, each class of these causes separately.

1. The sympathy which exists between the different organs of the body. The fact that when one organ is disordered in any way, the other organs sympathize, or suffer with it, is familiar to every one. This sympathy destroys the simplicity of disease in two ways: in the first place, it gives rise to many symptoms at a distance from the organ affected; pain, for example, is often far removed from the disease which causes it: thus, pain in the right shoulder, from disease of the liver; in the knee, from disease of the hip-joint; and