Lastly, before I leave the synthetical method, I must refer to the synthesis of Endocarditis by the introduction of an organic acid (lactic) into the circulation of a healthy animal. It was originally thought that thus experimental research illustrated the cause of acute rheumatic affections; it was never claimed to do so by its author, and later enquiry has unquestionably, I think, put the origin of rheumatism back to a point of time preceding the formation of abnormal acid products, and has shown that such products are secondary, that is to say, are the results of the preexisting systemic derangement. I have endeavoured to show, in another place, that acute rheumatism is a true neurotic disorder, having its origin in a morbid impression made on the peripheral cutaneous nervous expanse, which, reflected to the cord, leads to all the subsequent symptoms, including the formation of abnormal products. Continued observations support this view, and none better than a fact I have lately ascertained, namely, that between twenty and thirty athletic men were rendered subject to acute rheumatism by being exposed to cold and friction, applied to the surface of their bodies. The lactic acid synthesis of acute rheumatism must then, in my opinion, be set aside, but not so in regard to that sequel of rheumatism, endocardial inflammation: on this point the synthesis established has been so certain, that the endocardial murmurs have been produced, the inflammatory states of the membrane have been traced through all their stages, and the chronic effects followed out to the end. Thus we are left by the means of a synthesis, as beautiful as any of the before-mentioned examples, with the information that a product of the primary derangement, called Rheumatism, may, by a known means, excite the secondary derangement, called Endocarditis. In the present era many advances have been made in the methods of diagnosis, and although no single method can be considered great, in comparison I mean with such a grand discovery as auscultation, yet, in the combination of several methods, we have a sum total of advancement that will probably look well in the next page and stage of history. The first and most important of these means is the Thermometrical; the application of the thermometer to the detection of some obscure forms of disease: but the usefulness of this instrument does not stop here, for, whilst diagnosis is the means by which we are able to arrive at our prognosis, the thermometer is of immense service in guiding us in respect to prognosis. To me this point has been matter of study for several years, and I know of no enquiry that has afforded more positive answerings. Is one in doubt as to the premonitory stage of tubercle? does physical examination by the stethoscope give an equivocal reply ?—there is the thermometer by which to solve the difficulty. Does one, after a case of “shock,” or "surgical operation," wish to know the earliest indication of real danger ?—there is the thermometer to tell us that the danger is imminent, or even that it must be fatal. Do we meet with deceptive symptoms of fever? again the thermometer is our guide. A man is brought into the General Infirmary at Stafford to be under my care, and there have been periods when he seemed so well, before I saw him. that he was considered to be in no kind of danger; but then I find, on enquiry, that there have been other periods of his illness when there has been what is called " high fever," followed by intense depression. A case, you may say, of relapsing fever. Yes! I learn that on two occasions he has had an elevation of temperature during the day up to 1052 Fahr.; on another occasion, he had a second rise of temperature on the same day, and the mercury then stood at 107 Fahr. On the thirtythird day of his illness, the morning temperature was 96; rising to 103 at two p.m.; and falling again at five p.m. to 100; at eleven p.m. the thermometer marked 106: and altogether the instrument gave a series of such ugly variations that my experience told me I must augur the worst, as there is, as yet, no known remedy with which cases showing these extreme variations of temperature can be met. Unhappily, the thermometer told but too truly, for the man died. Take another case-a young woman is brought into the same institution labouring under well marked enteric fever, with a morning temperature persistently higher than the evening temperature: again my experience bids me pronounce unfavourably as to the termination of the case, and again the truthful thermometer is correct-the poor patient dies. I could multiply and multiply these experiences of the uses of the thermometer in disease, but the labour is unnecessary, for they are your experiences as well as mine. I am fully prepared to admit that an undue importance has been given to the Laryngoscope, not to it as an aid to a particular diagnosis, but as a general sign of advance in scientific medicine. I am not therefore, going to extol this instrument as if it were an instauration, or, indeed, anything more than a clever use of a reflector—an extension of a practice that has long been known to, and carried on by, the dentists, as well as in various kinds of physical experiments. On the contrary, I can but feel that medicine everywhere showed an unnecessary weakness in the appreciation of first principles of advancement, when she lent herself, so urgently and wonderingly, as she did a few years ago, to anything so essentially small. At the same time, to be quite fair, the diagnosis brought out by the laryngoscope has served some useful purposes. For the discovery of foreign substances lodged in the upper part of the air passages, for the detection of morbid growths in the same parts, of morbid conditions of the vocal cords, and of ulceration of the glottis, the laryngoscope supplies us with an instrument which, now that we have it, we could not conveniently spare. The Ophthalmoscope, really an instrument of our own time, stands in a much higher rank of discovery as a means of diagnosis. The instrument, simple as it is, is, I mean, the product of a higher physical induction, and the results of its employment lead to a deeper insight into internal changes of structure. The ophthalmoscope pierces beyond the retina, though it illuminates that nervous expansion only, for, by inferential teaching, it reveals to us the inner vascular changes, and changes of nervous matter in the cerebral centres themselves. Briefly, this instrument, commenced for the special purpose of enabling the ophthalmic surgeon to recognise the structural diseases within the globe of the eye, has become now of so wide an application in the hands of the general physician, that it promises to rank, as an instrument, next only to the stethoscope in physical diagnosis. Just as an illustrative case I may mention the following. A man was admitted as an in-patient at the Stafford Infirmary under my care: he complained of continued, and sometimes very severe, pain at the left side of his head. His general health appeared good. He had had syphilis. For many months he had been treated for neuralgia (tic), and had swallowed no inconsiderable amount of iron and quinine. An ophthalmoscopic examination of the left eye showed white optic atrophy, with considerable cupping of the disc; vision was very imperfect, although, strangely enough, he was not aware of this until the examination was being made. The diagnosis arrived at was tumour in the left side of the brain, probably in the neighbourhood of the optic tract. After being in the Infirmary nearly three months, the sight of the left eye having been quite lost, he died in a fit whilst in bed. The post mortem examination revealed a gummy tumour completely obliterating the left middle cerebral artery, accompanied with softening of the entire left cerebral hemisphere. Thus much for the ophthalmoscope. An instrument of our time, now very much neglected, except at quiet corners of great metropolitan thoroughfares, where it may be tried for a penny, is the Spirometer, invented by the late Dr. Hutchinson. This instrument, as a measurer of vital capacity, and as a by no means indifferent measurer of vital power, has passed, I think, into disuse without deserving the neglect. It is a good instrument; too clumsy, I doubt not, in construction, and, in this respect, unpopular, but most valuable when correctly employed. Like the thermometer it is a most important aid in the discovery of tubercle in doubtful cases. It affords the most telling record of the amount of pulmonary damage in cases of emphysema, and it has developed some singular physiological facts which have yet to be properly worked out one specially; that capacity of respiration is greater in tall than it is in short persons, although, in the latter, the circumference of the chest may be relatively larger. The Sphygmograph, introduced amongst us in recent years, has yielded readings infinitely curious, if not, as yet, peculiarly practical. Its application, generally, is limited by its complexity, and, if I may be so bold as to say it, it gives us what we do not always want, and it does not give us what we always do want. If it could be simplified in construction, and could be so arranged that it would register for us the precise number of strokes of the pulse per quarter minute, together with the exact power, or force, of the pulse, so that from visit to visit we could be accurately taught on these two points, we should have an aid of great value. But it may be, that, as it is, some leading discoveries have to be made with it for the benefit of the working practitioner. For these we must wait. Electricity, as an aid to diagnosis, is one of the latter day improvements to which I need to direct attention. The use of the minor telegraphic arrangement for the detection of metallic sub stances in gun-shot wounds; the use of the metallic brush and dry conductor for testing degrees of sensibility of the surface of the body; of the interrupted current for proving the continuance of muscular contractility; the employment of moist conductors for determining the relative failure of particular muscles in paralysis, -these are advances, simple, but ready to hand, and often satisfactory in the lessons they teach. Lastly, there is the most recent improvement in the art of diagnosis, the application of Ether Spray for testing the vascular tension of parts of the body, or of the body as a whole. We try by this method, what resistance the nervous surface can offer to an extreme degree of cold suddenly applied, and we find in proportion to the feebleness of resistance the rapidity of the action of the cold as shown by freezing of the part. It has in this way been shown in a case of paralysis, that, whereas in the healthy parts of the subject a resistance of nine seconds was offered, in the paralysed parts the resistance was overcome in two seconds. Here we have a new instrument of diagnosis; so new that we all have to learn its utility. These aids are all historical steps in our medicine of to day ; they are little steps, but distinct, and, unless they become overshadowed by some new and grand generalisation in diagnosis, will stand out demanding recognition and receiving continued improvement. They are faithful indices of the age altogether, of an age weak in grandeur of conception of natural things, but strong by, and through, its mastery of many minor ingenious contrivances, which massed together bespeak power as "Sands make the mountains, Every epoch in physic is marked by some great achievement in surgery: for surgical art is so purely experimental, and progresses so steadily from one point of venture to another more daring point, that it must move on independently of theory, or even of physiological discovery. Thus, one age introduces the ligature for bleeding vessels, another introduces transfusion of blood, another the process of cutting for cataract, another the tying an artery for aneurism, and so on. As a rule, a single age, nay a century, has developed |