what are called the principles which Dr. Weber had advocated and the reasons I advanced for introducing actinic light into bedrooms. Certainly no such views as are given on this subject in my book are to be found in the Croonian Lecture, or, I think I may say, in anything Dr. Weber, or any physician, has given to the world. It may be added that there is nothing to indicate that any such views were ever contemplated even; and, as will be seen, for a very sufficient reason.

No doubt the "sun-cure" has from time immemorial been more or less in vogue in the treatment of the phthisical. Indeed I cited from his Croonian Lecture Dr. Weber's views as to the great value of this mode of treatment when carried out according to his method-the essence of which consists in persistently exposing the consumptive as much as possible to the solar rays, and in providing them with "sunny rooms, sitting as well as bedroom." But the only principle, it has to be observed, upon which this latter treatment is advocated, is "that, though the sun does not shine at night, the vivifying influence which it exercises on the bedrooms during the day does not disappear at once with the cessation of the sunshine, but lasts through the night and longer."

Dr. Weber's improved plan of "sun-cure" is excellent, and a great advance in the treatment of consumption. The practice of systematically filling the patient's bedroom with sunshine I believe originated with Dr. Weber, and he is entitled to all the credit of it; but when we come to look into the one principle given for the practice, we find it absolutely void for uncertainty. The explanation of the beneficial effects of the sun wants explaining: "vivifying influence" is intangible, and may mean anything or nothing. One can get no notion of what it is or how it operates. In short, the principle of the "sun-cure" is but a phrase-a fair example of a class of phrases to which physicians, through the necessities of their position, have to resort.

The inferences I reached concerning the value of the sun in consumption were stated definitely enough. Right or wrong there could be no mistaking their plain meaning; and the only

question about them is the momentous one as to their soundness. I submitted that the solar beams admitted (in certain numbers at certain periods of the day) into the bedroom of the phthisical patient, destroy (in one or other of several ways that were discussed) the parent-forms of the tubercle bacillus, or the bacillus itself, growing in certain positions on certain soils in the room; that there is, consequent on this destruction, an estoppal to the air-poisoning of the room; that the lungs of the patient, being thus freed from further introductions of the specific vegetation, soon begin to repair damages; and that if this state of freedom from fresh invasions of the parasite is maintained, active parasitism ceases and the lesions are patched up or a radical cure is effected.

Nothing could well be more dissimilar than the two principles on which the use of the sun is based-the one that sunshine has a vivifying influence (presumably) on the patient, the other that the chemical rays of the sun have a destructive influence on the specific agent outside the patient.

Further, I submitted that whether my interpretation of the principle of the "sun-cure" was or was not correct, the practice of it obviously admitted of extension to "sun-prevention." Whatever the principle underlying this plan of treatment for those who are actually consumptive, the plan itself is logically applicable to those who, although as yet unaffected with tubercle, belong to what are called "consumptive families" (or to those who are living in what I consider to be consumptiontainted houses). For if the real practical value of the sun be assured, about which there can be very little doubt, it is not only fatuous to keep those who are supposed to inherit consumption in sunless rooms until tubercle is actually deposited in their lungs, but it is eminently absurd that anybody who can avoid it should sleep in a room insufficiently sunned long enough to "acquire "as so many persons under such conditions do—the "phthisical constitution." Letting the principle go, if the effects of admitting the sun freely into the bedroom are to stop a parasitism already established in the lung, a fortiori the same effects would have precluded the establishment of the parasitism.

Yet I cannot find, and I think it will be difficult to make out, that any writer before myself had proposed to utilise the sun for the express purpose of preventing phthisis either in those with, or in those without, the (hypothetical) "taint," or the (imaginary) "natural" or "acquired" "phthisical constitu tion." So far from Dr. Weber having strenuously advocated anything of the kind, there is nothing in his Croonian Lectures to indicate that he contemplated the immediate and permanent application of his own excellent method, even to the (as yet uninfected) brothers and sisters of a declared consumptive in a “tainted” family, and much less to the "collaterals" and the whole kith and kin of the family. It is hardly necessary to add, therefore, that he nowhere hints at any possible good from extending his principle of vivifying influence to such of the general population as are condemned, or condemn themselves, to sleep in darkened rooms, and are thereby exposed to the serious risk of becoming consumptive: although it is a forced conclusion that if the sun will cure, it will also prevent consumption.

Omitting all reference to the question of determining what is a sufficiency of chemical light for a bedroom in a given latitude (and it may be remarked that physicians have not yet discriminated in regard to the relative value of the sun's ray at different periods of the day in different seasons in the same place), sufficient has been shown of the framework of one1 of my plans for the prevention of consumption. And I submit with some confidence that the plan had not been suggested before; whilst it must be patent that the principles upon which the plan was based were enunciated for the first time in my work, inasmuch as no one had previously challenged the soundness of Koch's inference respecting the botanical position of the bacillus. A wide distinction, I apprehend, is to be drawn between a plan with a definite principle at its back for the

1 It is not the only plan. Several plans of destroying and precluding the specific vegetation in rooms are suggested in my book, as well as that by sunlight; for it was obvious that this agency is not always available, practically, in cities.

prevention of consumption, and an ordinance, which must be described as empirical, for the cure of consumption. If a mere rule of thumb handed down through centuries and applied in the treatment of those who are actually stricken with the disease, or who may have obscure signs of tubercle in the lung, is to be looked upon in the same light as a proposition for the prevention of phthisis amongst all classes by a method founded on at least an intelligible, if not a rational or sound, conception of the causation of the malady-then, undoubtedly, the "principles " I advocated have "long been advocated by physicians." And if anything were wanting to show the immense distance between Dr. Weber's principles and mine in this matter, it is to be found in the fact that Dr. Weber is a decided contagionist, and that I am a non-contagionist of so advanced a type that, in a "consumptive family," I take the family house and not the family blood to be "tainted."

Reviewers, however, have not the space, or cannot always be at the pains, to differentiate on nice points. Therefore the only comments I shall make on the statement that " our author, too, has adopted very largely the views respecting the nature of phthisis which were enunciated a few years back by Dr. Andrew," are, first, that the significant word too in this sentence, by suggesting that I had "very largely adopted" the principles of Dr. Weber as well as the views of Dr. Andrew, intensifies the impression left by the previous sentence, that I had merely followed on the old track, and in the very footsteps of Dr. Weber-or, in plain language, that I had been openly pirating in Dr. Weber's special domain. True this may not be the proper construction of the words, or the construction that it was meant should be put upon them; yet, as it is one of the constructions they will bear, most of those who consider they have the gift of being able to read between the lines—a common failing with us all-will not have omitted to put this ugly construction on them. Hence I have been impelled to point to yet another construction that may be found between the lines.

Secondly, I frankly admit that I borrowed freely from Dr. Andrew's superb contributions to the literature of phthisis. I

not only drew on his store of facts for purposes of illustration, but I reproduced such of his argument as concurred with mine, thankful to have support to that extent from such an authority; and I gratefully acknowledged my indebtedness. The words "very largely adopted," with their context referring to this, may, however, be taken to imply, or may be twisted into the implication, that I had merely reflected or slavishly clung to the views of Dr. Andrew, or had adopted them wholesale without question—that I had in fact simply echoed the Lumleian Lectures, and that, as it was not necessary to observe, second-hand work of that kind was not of much account. From all which it is a sequence that in regard to "the nature of phthisis" the views I submitted had long been under the consideration of etiologists, and that consequently it was somewhat superfluous to have obtruded them upon their notice again. I am constrained therefore to say that I have profound respect for the work done in this field by Dr. Andrew, and let it be seen plainly in my book; but this was not incompatible with an independent line of thought. It will be found in my observations on his lectures that I was not deterred from suggesting wherein it appeared to me his argument in certain respects was deficient, or inconclusive. My main contention was in no way dependent on Dr. Andrew's views, and would have stood without them; but searching as I did in every direction for material to strengthen it on all sides, I was only too glad to find in the Lumleian Lectures collateral evidence that bore with so much weight on one side. On other sides of the same question, however, Dr. Andrew's views and mine are as wide asunder as the poles. Moreover he has not glanced at some aspects of the nature of phthisis to which I gave large attention. As all this admits of easy verification, I do not wince in the slightest in regard to having "very largely adopted Dr. Andrew's views and Dr. Weber's principles."

The allusion in the review to my being like all enthusiasts somewhat too "hopeful" and so forth, and the decision that the realisation of my plans for the prevention of consumption are "absolutely impossible in our overgrown cities," were, I