ease-pain all over and surrounding the mastoid process, otorrhoea, deafness, large perforation of the membrana tympani; added to these the history I have above detailed. Having carefully considered the case, it was evident to me that the line of treatment calculated to relieve him was trephining. And confident of disease existing, and pus being present without sufficient exit, on Dec. 7 I made an incision such as I have described, and selected a trephine somewhat smaller than that used in the former case. I placed the lower part of the crown on a level with the external auditory meatus, and thus opened the mastoid cells and the tympanum, and exposed the envelope of the brain which comprises all the rest of the membrane. This lax portion is the most frequent seat of perforation. The patient had pain round the mastoid process, and on tapping it considerable pain, especially at a point corresponding to the posterior root of the zygoma, but inferior to the latter. When the ear was syringed and cleansed further discharge would flow by getting the patient to forcibly blow his nose. The otorrhoea was of comparatively recent duration. He stated he was quite well four months previous to admission, when he had an attack of fever, which, he said, was typhus. On recovering from this the purulent discharge commenced. He had some pain at the back of his ear, but it was never much. Having the dura mater; the pus actually welled up. come to the determination that disease existed in the mastoid cells, I made up my mind to operate, and on March 3, the patient being under the influence of ether, I made an incision from the upper part of the mastoid process in the direction of the posterior root of the zygoma and a little above it, and continued this in a semicircle downwards, close to the pinna, and a little below the external auditory meatus, and dissected all back towards the mastoid process. I then placed the crown of a trephine on a level with the external auditory meatus, and removed the piece of bone shown in the accompanying Plate, Figs. A and D. The disease on its internal surface is evident. The upper portion, it will be perceived, is eaten away. By the removal of this piece of bone the mastoid cells were opened, the tympanum also, and the dura mater exposed. Pus did not flow from the wound for 23 hours, when the discharge from the ear lessened, and finally ceased. For two or three days after the operation he had some pain down the right side of his neck, which was relieved by opiate fomentations. In one month the wound was closed, and he left perfectly well. I saw him within the last week; he is in excellent health. Nothing could have been more satisfactory. The bone shown at Fig. B is a good specimen of carious disease. Two points of suture closed the wound above, the lower edges were kept separate by a small piece of lint, a hot flannel fomentation was placed over the wound, and the side of his head covered with oil-silk. The patient was then removed to bed. Pus continued to flow through the wound; the discharge from the ear lessened. The patient's temp. on night of operation 98.8°; pulse 88. Stated that he was not suffering pain, and he slept well subsequently to the operation. Left completely recovered, and is now well. CASE 3. T. H., blacksmith, Oct. 17, 1883. Strong, well-built, about six feet high, and perhaps æt. 35. Was suffering from deafness and dizziness. There was considerable swelling over the right mastoid process, accompanied by pain and redness; also the part pitted upon the application of pressure. Could not give any history of an injury; had, however, suffered when a boy from scarlatina, which was followed by deafness. Trephined him Oct. 25, when, upon the removal of the piece of bone, matter welled out copiously, apparently from both the mastoid cells and the tympanum. The wound healed by granulation, and his highest temp. did not exceed 99°. Discharged cured Dec. 1, 1883. A month ago I was informed that he was in active employment and in perfect health. The internal and external surfaces of the bone removed are shown in Figs. C and F, in the former of which evident osseous disease is palpable. CASE 2. M. F., 41, Nov. 27, 1882. He had always been healthy. Some 13 or 14 years ago he had a running from his right ear, which stopped suddenly. He thought no more about it. Last Nov. he got a severe cold, and had acute pain in the region of his mastoid process; the entire side of his head became painful; he could not bear to have it touched, and got no sleep for more than eight days. He was told Acute inflammation of the mastoid process, it was erysipelas; and after about a week, which the subject of the second case I have during which period he suffered intensely, a detailed evidently suffered from, is not common purulent discharge came from his ear. He in the adult, but is more usually seen in the then got some relief. Before his admission, I young. Of 67 cases collected by Mr. Buck, of am informed that during the acute symptoms New York-13 were 10 years old or younger; he was dull, and did not answer questions asked of him, until repeated two or three times-in fact, he lacked response. This patient exhibited all the signs of osseous dis 26 were 10 to 25; 9 were 25 to 40; 12 were 40 to 55; 7 were 55 to 60. The youngest was eight months old; the eldest 62 years. The idea of perforation of the mastoid cells and galvano-cautery over the mastoid process; The site I would always select for operation, PATHOLOGY OF SUPPURATIVE IN- BY JOHN LINDSAY STEVEN, M.D. dates from Vesalius, who was amongst the In an article on Consecutive Nephritis, in Reynold's System of Medicine, Mr. Marcus Beck makes the following remarks with regard to the shape of the purulent points: The abscesses, and the pale streaks between them, naturally assume a wedgelike form, in consequence of the anatomical arrangement of the structures amongst which they are situated; but this is very different from the form of an embolic abscess. In embolic patches the width of the base is seldom less than half its length, but, in these abscesses of interstitial nephritis, the base showing on the surface may be only the width of a pin's head, while the length of the wedge may be one inch or more. Embolic the pyramids." With regard to the present shape of the suppurative areas was specially microscopic examination, the inflammations in well seen in Case 6, in which the inflammatory the kidney substance presented, with one or process extended in a long and somewhat two exceptions, pretty similar appearances to straggling manner from the capsule right those already described in connection with the through the cortex to the pyramid. In the other varieties. In their elongated and pyrastained specimens this appearance could be midal shape and cortical situation, they differed FIG. 6. detected quite well by the naked eye, owing to | from the suppurations occurring as the result the inflammatory corpuscles taking up the of the entrance of the virus into the uriniferous micro-organisms were discovered in large numbers. In Case 2 they were present as small colonies in the neighborhood, or interior, of the abscesses. In Case 4 the colonies were of very large size, and the individual organisms, though very minute, were distinctly rod-shaped, thus differing from the ordinary rounded shape of the micrococci (fig. 7). It may be remarked in passing, that the inflammatory changes in this kidney seemed to be much more extensive and severe than in the others. In Case 6 the micrococci were scattered amongst the leucocytes, and were not grouped into distinct colonies. In Case 2 the capsule, which had been only partially removed at the post-mortem, presented microscopic appearances of very considerable importance as bearing upon the mode of infection. It showed well defined areas of leucocytes in its substance, which were strikingly similar to those which have already been described as existing in the external layers of the bladder and ureter. It also contained numerous capillary blood-vessels, outside many of which leucocytes were seen grouped in large numbers. In its substance, too, numerous colonies of micrococci were observed, and these were frequently seen lying in the lymphatic spaces surrounding the small capsular blood-vessels. As has been already noted, the small abscesses were often observed to involve the capsular as much as the renal tissue, the whole appearances being strongly indicative of the fact that they had primarily originated in the tissue of the capsule itself, and afterwards passed inwards to the substance of the kidney, as is well shown in fig. 6. As second, and, in order that the state of matters The next question is-How has the infective virus obtained access to the kidney in this class of cases? It is obvious, from what has just been said, that the route is different from that described in the previous subsection-that in fact we have two distinct modes of infection -viz. (1), by way of the tubules, already discussed; and (2), (the mode at present under review) by the lymphatics. I do not find this distinction clearly insisted upon by any of the writers I have yet been able to consult. Thus, Klebs distinctly recognises the entrance of organisms by the tubules, and states that they may make their way into the interstitial tissue from them. Dickinson also holds that the virus enters by the uriniferous tubules, then passes into the veins, and is thus sown broad-appearances after injection of the kidney from cast through the organ. And Marcus Beck, the ureter. These observations are very while he recognises that the lymphatics are in- strongly confirmatory of the opinion to which, volved in suppurative nephritis, also holds that as the result of purely pathological researches, the septic material first passes into the urinif- I had long ago come, that the lymphatics of erous tubules. Each of the opinions just stated the ureter, and those of the cortex of the kidney, might be applied to the first mode of infection communicate directly with one another. I re-viz., by the tubules—but none of them to the|peated these experiments, and injected three human kidneys from the ureter. Instead of carmine and gelatine, I used the cold Prussianblue injecting fluid, as I thought it would more easily run through the very small vessels. The injection was made by means of a continuous injection apparatus, the pressure employed varying from 4 to 8 cms. of mercury. The first effect was that the pelvis became greatly distended, then the blue fluid was seen to be making its way through the substance of the wall of the pelvis and the spaces of the renal capsule, and gradually filling up small starshaped or tortuous vessels on the surface of the kidney. In one of the experiments a vessel in FIG. 8. the pelvic wall of considerable size was seen to get slowly filled and stretch away over the surface of the kidney. On a little air getting by accident into the apparatus, minute air bubbles were seen to chase one another through this vessel, which was about the diameter of a fine sewing needle. The time employed for injection varied from 15 minutes to 2 hours, then a ligature was put on the ureter, and the organ was placed in weak spirit and water for 24 hours. Upon examination at the end of that period, the surface of the kidney presented a number of delicate star-shaped or tortuous vessels, which were filled with the blue fluid, and which were very distinct from contrast with the general red coloration of the surface. A fair idea of the appearance is obtained from fig. 8. Upon section the cortex was seen to be traversed by minute blue streaks, leading down from the injected vessels on the surface. Sometimes these streaks were long enough to reach the pyramid, but as a general rule they were not so long. In a few cases the lower half of the pyramidal uriniferous tubules had been injected, but the injection never went nearly so far up as the cortex, see figs. 9 and IO. Upon microscopic examination similar appearances to those observed by Mr. Smith were seen-the blue coloration was found to be situated in the spaces between the uriniferous tubules, and to get gradually less the farther from the capsule it was. See fig. 11. These facts, then, taken along with the observations of Dr. Newman, render it almost certain that the lymphatics in the cortex of the kidney, and those in the wall of the ureter are intercommunicable, and, bearing them in mind, my theory as to the infection of the kidney by means of the lymphatics is readily understood. One of the primary factors in the process of infection is the greatly inflamed mucous membrane of the bladder, in which, as has been shown, septic organisms proliferate in great numbers. From this breeding ground the infective material passes outwards by means of the lymphatic spaces through the bladder wall, and the micro-organisms are then found abundantly in the external layers, often having excited inflammatory changes in their progress. The organisms then obtain access to the lymphatic channels in the wall of the ureter, and gradually spread upwards; here also, as has been seen, often exciting localised patches of inflammation as they go. The mucous membrane of the ureter may perhaps be somewhat inflamed, but, in order that the kidney should become infected, it is not at all necessary that the mucous surface should be involved. That this is so is abundantly borne out by Cases 6 and 8 of the appendix, in which the mucous membrane was only very slightly or not at all affected. At length the.organisms reach the pelvis of the kidney, and then pass into the lymphatic spaces of the capsule, in various parts of which, as the result of their virulent action, small abscesses form. These abscesses also involve the superficial parts of the renal cortex, and the morbid products are gradually disseminated through its substance, exciting the inflammatory formations in the way already seen. The fact of the abscesses being so frequently met with situated between the capsule |