DISCUSSION DR. C. H. HUNTER (Minneapolis): I would not undertake the discussion of this paper because the subject has already passed from the hands of the general practitioner into those of the specialist. We are willing to turn it over to those who are particularly versed in this matter, and it probably will be made the part of a public functionary's business to attend to a great many details in these matters of prevention, so, of course, a minute knowledge of some of the matters of individual prevention should be of practical value to us all. There was one feature of the paper that struck me with particular interest, and that was as to the suggestion for sweeping and cleaning public buildings. Through the public prints we learn that Dr. Corbett has been conducting some studies in this matter that are or should be of the most lively interest, especially so in regard to the sweeping of hospitals, and next in importance the sweeping of school rooms. While the matter of sweeping is not really the subject-matter of the discussion tonight, I would be very glad if Dr. Corbett could outline the conclusions he has come to, if any, and give us an idea of what he bases those conclusions on. I have nothing further to add, but I would be extremely interested if, in closing the discussion, he would give us some information on that point, because it would be of general interest. DR. J. FRANK CORBETT (Essayist): In regard to cleaning of school houses, we tried a series of experiments to determine the relative number of bacteria in the air of school rooms after various methods of cleaning, namely, dry sweeping, sawdust sweeping, and scrubbing; also after dry sweeping with fan ventilation, after dry sweeping with open-window ventilation. We found the ventilation to be a very important factor. Only one-half as many bacteria were found with fan ventilation as with open windows. Sawdust sweeping gave returns that were disappointing. This was probably due to the sawdust being retained in the cracks of the floor and about the legs of desks. The best results were obtained by scrubbing. I regret not having a chart here showing all details. SUBPARIETAL INJURIES OF THE KIDNEYS, WALTER COURTNEY, M. D. Brainerd In the limited time allowed for the reading of papers, it will not be possible to extensively consider the literature of the subject, and therefore the writer will not attempt to do so. This subject has had attention among surgeons from comparatively early times. Gittler of Leipsic published a special work on kidney injuries as early as 1596. Rayer of Paris (1793-1867) gives an excellent résumé of the literature of the subject up to this time, with an account of ten cases of wounds and thirteen cases of contusion and rupture of the kidney. Herman Maas, of Wurzburg, (1842-1886), published in the Deutsche Zeitschrift für Chirurgie, Vol. 10, 1878, an account of an experimental inquiry into the effect of artificial rupture of the kidney in animals. He also published a collection of 72 cases of injury to the kidney in man, and stated that of that number, 34 patients died of their injuries. Keen of Philadelphia, in the Transactions of the American Surgical Association, 1896, reported a collection of 117 cases, covering the period from 1878 up to 1897. Davis of Chicago, in the Annals of Surgery, Vol. 36, for 1902, reports a collection of 35 cases of ruptured kidney, one of which he treated himself, covering a period of five years, 1897 to 1901, inclusive of both. This collection is sequential to Keen's, and I am not aware of any other since. Notably among the names of other writers on this subject stands that of Henry Morris. The section on "Subparietal Injuries of the Kidney," in his book, "Diseases of the Kidney," is one of the most valuable in medical literature. These injuries of the kidney are comparatively uncommon. Few surgeons have seen many cases, and some who have been in active surgical practice for years, have not met with even a single case. In the sixteen years of my service as surgeon in charge of the Northern Pacific Railway Hospital at Brainerd, and as Chief Surgeon of the Eastern Medical Division, consisting of about one-half of the mileage of the system, I have encountered only two actual cases of subparietal rupture of the kidney. Doubtless there have been others among the early fatal crushing injuries, which did not come to operation or autopsy. We have, however, observed several cases of contusion unaccompanied by laceration or rupture, and where transient hematuria was the principal symptom. This experience, combined with a review of the literature, at command, inclines me to the belief that railway employes are not more liable to subparietal injuries of the kidneys than men in other walks of life. My third case occurred in the person of a farmer. Subcutaneous injuries of the kidneys may be divided, according to the degree of severity, into (a) contusions; (b) lacerations; and (c) complete rupture of the organ into two or more portions. In contusions, the injuring force may have been only sufficient to disturb the structure of the kidney to the extent of causing an extravasation of blood and consequent hematuria. Of these cases I believe I have seen several. In lacerations the injuring force, while greater, may have only resulted in more or less extensive tearing or lacerating of the parenchyma, with or without a similar and simultaneous effect on the capsule or pelvis. Primary laceration of the kidney substance only may be secondarily followed by a solution of continuity in the capsule with resulting urinary effusion. Case 1, in the writer's report, is a case in point. In ruptures the injuring force may have been so severe as to have partly or completely separated the organ into two or more fragments, torn the main vessels, and, in addition, lacerated or ruptured contiguous or remote or gans as well. Subcutaneous injuries of the ureter are exceedingly rare. Morris, in his Hunterian lectures, for 1898, states that he has only been able to collect 23 cases. These injuries occur much more frequently in males than in females. This is no doubt due to the more active habits of the sterner sex, whether men or boys. The cause of these injuries may be either direct or indirect violence. Direct violence may be due to a fall from a height, and striking some prominent object, like the edge of a manger; the kick of a horse, the passage of a cartwheel across the body, a blow from a wagon pole, etc. Prince A. Morrow says ("Genito-Urinary Diseases," etc., Vol. 1): "The common, direct cause is a fall from a height.” Two of the writer's cases received their injuries in this manner. Indirect violence may come from extreme muscular action, as in forcible flexion of the trunk or other contortions of the body; from a fall, striking on the feet or buttocks, and causing severe jarring. Accompanying these injuries there may be also laceration or rupture of the liver, spleen, lungs, and intestines. If the force is applied over the abdomen, from the front, there is great danger of the peritoneum being torn. This is particularly likely to happen in children, because of the absence of perirenal fat. SYMPTOMS Where there has been no more serious injury of the kidney than a contusion, hematuria is the principal symptom. In the cases I have observed, the history of the injury led us to collect, measure, and examine the urinary secretion, and on detection of blood, and the absence of any other particular sign of trauma, a diagnosis of contusion was made. The hematuria is transient usually, and the patient but little indisposed. The principal diagnostic symptoms of ruptured or badly lacerated kidney are pain, hematuria, and tumefaction. Shock, more or less severe, is usually severe at first, and confined to the region of the injured kidney; later it radiates to the groin, testes, and bladder. The regional muscles are tense, and the patient inclines to a fixed posi tion. Hematuria is present in most of the cases, the exception being where the ureter is plugged by clot or ruptured, or the kidney divided transversely into two fragments. The presence of blood in the urine may be slight at first, and increase later on; or be intermittent, with an interval of even several days between. Diminished discharge of urine, for a time, is not infrequently observed. Sometimes blood coagulates in the bladder, and prevents micturition. Casts of the ureter are sometimes found in the urine. Complete suppression or anuria is probably due to rupture of both kidneys. Tumefaction and extended dullness in the loin, appearing soon after the injury, is indicative of rupture and hemorrhage. If the tumefaction comes on slowly and is distinct as to outline, the probability is that the hemorrhage is intracapsular. Late tumefaction is likely to be due to urinary effusion or abscess formation. Hemorrhage is seldom so extensive, soon after the injury, as to cause death, unless the renal vessels and peritoneum have been torn. Ecchymosis in the region of the loin has no special significance, but when present at the external inguinal ring, is pathognomonic. Anemia will be proportionate to the amount of hemorrhage. Peritonitis is not likely to occur early unless there has been an injury of that organ and the intestine as well. Writers seem to disagree as to the value and presence of shock. Some say it is usually present in quite a marked degree, and others say it is not a characteristic symptom. When present in a marked degree, it is doubtless indicative of extensive hemorrhage and severe injury to other internal organs, as the liver and spleen. Vomiting may or may not be present. The late symptoms of particular value are those indicating sepsis and are not necessary of description here. DIAGNOSIS In contusions of the kidney, the diagnosis may be made on the history of the injury and the presence of hematuria. It is well to remember, however, that hematuria may be the result of dislodgment of a renal calculus, disturbance of a |