It will, I think, be found, that most physicians who have begun their practice with a large employment of active purgatives, abridge this more or less as their experience is matured by time. No physician, indeed, as I have before said, can rightly relinquish the benefits of this treatment, boldly and vigorously employed, in certain cases of disease; but the limitation of such vigour to actual disease is that which a wise experience will teach, as the general rule of practice. It is a rule, indeed, like all others in medicine, with many needful exceptions. One of the most frequent and reasonable of these regards the use of laxatives with direct reference to the prevention of disorder; as in those cases where, from constitution or habits of life, there is strong tendency to accumulations, morbid or otherwise, in the vascular system, and to various forms of deposit in the body. Here full purging, at certain intervals (and these may often most usefully be made periodical) is the best safeguard we have against great contingent evil. The gouty temperament, when strongly marked, may be taken as an instance in point. But here, too, the same principle must be kept in mind, and forbearance be blended with our vigour; otherwise the prevention of one mischief becomes the source of many.

Nor can the need be doubted of aiding the natural action of the bowels in many cases where there is habitual costiveness, either from particular temperament or the casual condition of life. But I have already pointed out the great abuse by excess in this part of practice, and the importance of giving more scope than is usually done to the natural powers of the organs in retrieving any such casualties. I advert to the subject again, as well to enforce this, as also to suggest the value in these cases of the direct combination of tonics with aperients; a form of prescription which might well be brought into more general use. In the greater number of instances

of this kind, weakness in the proper action of the bowels is the cause of costiveness; and in seeking to remove the effect by means which act through irritation only, we do but add to the mischief. The tonic, conjoined with the aperient, enforces its action, without weakening the organs. These in fact are the cases in which, if there be no irritation of the mucous membrane, bark will itself often act as a laxative. I have known many instances where calomel, colocynth, and gamboge, in large doses, have had little other effect than that of injurious irritation; but where a few drachms of infusion of senna, with decoction of bark, have been amply sufficient in producing the desired action.

This practice is of more especial value in those languid and strumous habits in which strength and good digestion are so carefully to be maintained; and where an irritation, habitually repeated, often becomes the source of active and permanent disease.

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CHAP. IX.

ON METHODS OF PRESCRIPTION.

THE simplification of medicine, and of methods as well as principles in the treatment of disease, ought ever to be present to the mind of the physician. The more complex the objects before him, the stronger the motive for adopting and maintaining this rule. Even with all the curtailments and sounder views of modern practice, it must be admitted that more might yet be done in furtherance of the object. We have long abandoned those preposterous compounds, of which the number of ingredients, or the secret methods of admixture, formed the sole science: but the error is still frequent of aiming at a greater number of objects than can be reached at once, or by any single combination of remedies; thereby forfeiting the good to be derived from simpler and more explicit means. Secondary and subordinate symptoms are apt to usurp a place in prescriptions, due to such only as are essential to the character and course of the malady. And it is not too much to affirm that the judgment of the medical man upon a disorder is often warped by the reflection of his own practice. He is apt to look at the symptoms through his own previous treatment of them, as well as through the false opinions of those around; and the trifling or casual symptom of one day gains undue weight the next, from its needless admission among the objects for which he has prescribed, All this is natural in itself; but undoubtedly a serious error in practice. In no way can it better be obviated than by carefully simplifying the character of prescriptions; and

avoiding ambiguity, as far as possible, in the intention we assign to their several parts.

It is an opinion, not infrequent among medical men, that the multiplication of medicines in our hands adds in the same ratio to the power and facilities of practice. This view is admissible only in a very qualified sense. It is, in truth, as correct to say, that the addition of new medicines or preparations, which do not expressly accomplish new purposes, or fulfil more advantageously those already attained, becomes an incumbrance to the practitioner, and an impediment to the progress of the science.

It may be alleged, and must be fully admitted, that combinations have often effects not resulting equally from any of their ingredients. This is true as respects many vegetable medicines of powerful action, whether narcotic, purgative, diuretic, or alterative. It is especially true as regards chemical medicines, where changes of combination may occasionally be calculated upon, favouring the effects desired; though much more frequently the facts by which their use is determined are merely empirical in kind. The observation of these facts is obviously one of the most important objects to the practitioner. But it must be added, one of the most difficult also; for even in the simpler combinations we can rarely obtain that precise estimate of effects, which is so essential to the success and certainty of practice; still less can we do so in those of complicated kind. Each new ingredient added to a medicine increases in a higher ratio the chances of error, and obscures the evidence by which such error may be detected and removed. And the application of other science to this subject, though never to be lost sight of, is here made so uncertain by being subjected to vital actions, that it must ever be admitted with great caution, and wholly in subordination to experience. Several compound medicines, of undoubted efficacy, contradict che

mical laws even in the points where it might seem of greatest moment to maintain them.

The best general rule seems to be, to define in every case, as far as can be done, the main object of present treatment,to make this the basis of prescription, and to admit, subordinately and under limitation, all such means as apply to collateral symptoms. This rule ought especially to be kept in mind, when a new medicine, or new applications of an old one, are on trial in our hands. Complexity here, especially that which arises from the admixture of new agents in the same prescription, disguises that which it imports us most to know, and which is always learnt with difficulty amid the many conditions tending to obscure the effect. In adding to these the uncertainty of combination, which is itself in most cases an experiment, we wrap one doubt within another, and play false with every just principle of medical research.

Such recommendations may seem trite and trivial; yet are they justified by the rarity of a principle of prescription, consistent with itself, and giving due proportion to the objects in view. The fitness of a man's understanding for medical practice can in no way be better estimated than by looking to these points. The physician who allows his attention to be distracted by secondary symptoms, and hampers a powerful medicine with petty appendages, directed to subordinate objects, shows a quality of mind adverse to sound practice, and incapable of attaining any valuable truth.

Not in the technical part of prescription alone, but also in the examination of symptoms on which it is founded, much may be gained by a rule of inquiry. Vague and inconsecutive questions, whether from timidity in the young practitioner, indifference in the older one, or irregular habits of thought in either, are very generally useless, and often positively hurtful. They defraud the physician of his own judgment, and

put the