THE INFLUENCE OF THE DISCOVERY OF THE RELA- AWARDED THE SCHUYLER ALUMNI PRIZE FOR 1901. By H. JUDSON LIPES, M. D., Lecturer on Obstetrics, Albany Medical College; Obstetrician to the Albany Guild for the Care of the Sick Poor. (Continued from Page 149-Preceding Number.) ETIOLOGY. Scientists, and every one, in fact, in these days of progress, are not satisfied unless the causa prima of all effects is known. It was easy enough to satisfy earlier observers, and in ancient or in mediæval times all unknown causes were ascribed to the gods. The Greeks before Troy ascribed the presence of the great pestilence, which nearly devastated their armies, to the arrows of the offended god, Apollo. Camp hygiene at that early date was an unheard of subject and presented a problem as great as concerns our armies to-day. Homer, in the Odyssey, makes the father of gods and men say: "Lo, how men blame the gods: From us they say spring troubles. But, through their own perversity and more than is their due, they meet with sorrow." This notion that pestilences are punishments for sins, and that they can be combated by sacrifices, prayer and pilgrimages, survives to-day in the midst of civilized Europe-an example of the deep-rooted proclivity in untrained minds towards a search after the animate. Through bacteriology we have been enabled to determine, practically with certainty, the causes of numerous diseases, while we are still in doubt as to the specific germs concerned in other conditions. And not only have the causes been ascertained in many diseases, but the modes and portals of infection have been determined, which is of great practical value in the prevention and treatment of diseases. Then, too, as has been pointed out by various observers, there are certain conditions which may not be constantly associated with any well-defined group of clinical manifestations although caused by bacilli probably pathogenic under certain conditions. Let us first consider those diseases in which the specific germ has been discovered. Diphtheria. Perhaps, of all the specific diseases that have engaged the attention of physicians and bacteriologists, none has been productive of greater results, as we shall see further along in our discussion, than diphtheria. The diphtheria-bacillus was first grown in pure culture by Löffler, in 1884, although, as we have already stated, it was observed by Klebs the year before. The portal of infection for the diphtheria-bacillus may be constituted by any mucous membrane or wound surface, infection commonly taking place in the pharynx. Influenza.-Among the acute general diseases which have created a havoc the world over during the last ten years influenza is certainly at the head of the list. In 1892, Pfeiffer published a classical work on the cause of influenza wherein he accurately described the causal relationship between the bacillus and the disease, although Kirchner probably first saw the bacillus. This organism was first seen and isolated from the sputum of influenza cases during the great epidemic of 1889-90. Like a number of other infectious diseases, influenza was suspected to be due to some minute parasite long before the true cause was discovered, but failure to find the germ was due to the fact that it stained with difficulty; is an exceedingly small germ, and that it did not grow on our ordinary culture media. Tuberculosis.-Tuberculosis, the enemy of mankind and the most devastating of all diseases the world over, was commonly believed to be an infectious disease many years ago in some countries, but it is only within comparatively recent times that the infectiousness of the disease has become an established fact in scientific medicine. Villemin gave the first evidence of the infectious nature of tuberculosis by inoculation of tuberculous material. The tubercle-bacillus was discovered by Koch in 1882. What a hope was raised the world over when this discovery was announced. Every tuberculosis patient then anxiously awaited the cure which every newspaper promised. Still, while the results of this discovery were not so prolific as one might wish for, it has led to other investigations which will undoubtedly prove of greater importance. Asiatic Cholera.-Koch likewise discovered, in 1883, that the exciting agent of Asiatic cholera is the comma-bacillus. These comma-bacilli are found constantly in all cases of Asiatic cholera, and in innumerable amount; in part in pure culture in the liquid intestinal contents; further, in the intestinal walls of patients; and only exceptionally in other organs. The vibrios can be demonstrated in the feces on an average to the tenth day after the inception of the disease and have never been demonstrated in association with other diseases. Bubonic Plague.-Another disease which has attracted considerable attention during the past two years, in which the cause is positively ascertained, is bubonic plague. The exciting agent of the plague was discovered by Kitasato and Yersin during an epidemic of the plague in China in the year 1894. The plaguebacillus gains entrance into the human organism most frequently by way of slight injuries, scratch-wounds, etc. Infection through the skin may take place simultaneously at several different points of the body in the same case, and in all probability it can occur through the intermediation of insects. Much that we know concerning this disease is due to the work of the German commissioner who went to Bombay in the beginning of the year 1897. Relapsing Fever.-The cause of relapsing fever was, in 1873, found by Obermeier, a former assistant of Rudolph Virchow, and who died prematurely, to be a special spiral bacterium, which he designated the spirocheta of relapsing fever. Obermeier's discovery was the more far-reaching, because with it an organism of the class of bacteria was for the first time recognized as the cause of a human infectious disease. These spirilla are present, and in varying number, only in the blood of those suffering from relapsing fever, in which they appear a short time before the onset of the fever, multiplying rapidly during the continuance of the fever, to disappear, a short time before the critical defervescence, until the onset of the next febrile paroxysm. These spirilla are not ordinarily found in the secretions and excretions of patients suffering from the fever, and with equal variety outside the human body, they are, therefore, most rigid blood-parasites. Just how this disease is transmitted is yet unknown. Tetanus.-Nicolaier, of Göttingen, in 1885, recognized the exciting agent of tetanus as a bristle-like rod with a terminal bulbous spore, but it was first isolated by Kitasato, in 1899, from the foreign bacteria always asssociated with it in infectious earth and in pus from a case of tetanus and grown in pure culture. The portal of entry for tetanus-bacilli in human beings may be constituted by any lesion of the external integument. Before the days of aseptic surgery it was the frequent concomitant of operative procedures. In human beings the bacilli never enter the blood or the viscera, but remain confined to the site of original infection. Anthrax.-Anthrax, which is a disease of animals, particularly of sheep, is sometimes transferred to human beings through contact with animals suffering from this disease or from the cadavers of those dead of the disease. Tanners are particularly exposed to the danger in manipulating the skins of animals dead of anthrax. As early as 1849 Pollender, in Germany, and Rayer and Davaine, in France, in 1850, were the first, independently of each other, to detect bacilli in the blood of animals suffering from anthrax. The experimental development of the disease by means of the bacillus, however, was first successfully accomplished by Koch in 1876. Glanders.-Another disease peculiar to animals, but sometimes transferred to man, is glanders. In human beings, who, in the vast majority of cases, are infected by contact with horses suffering from glanders, the skin, without doubt, constitutes the principal portal of infection. From a pathologic-anatomic standpoint, glanders belongs to the group of diseases that, like tuberculosis, give rise to the formation of nodules that exhibit a marked tendency to disintegration and softening. The exciting agent of glanders was discovered in 1882 by Löffler and Schütz. Gonorrhea.-Gonorrhoea, a disease which formerly was treated by purely medical means, has now more or less passed into the hands of the surgeon. But the disease is so universal that we may at least call attention to its etiology. The exciting agents of gonorrhoea, the gonococci, discovered by Neisser, in 1879, are cocci which are separated into two distinct hemispheres by means of a dividing fissure. Gonococci are constantly present in secretion from all gonorrhoeal inflammations. Diseases caused by the Protozoa.-The protozoa, the lowest forms of animal life (consequently not "bacteria"-although as previously stated we believe the class of diseases caused by these parasites come clearly within the limits of our subject), have hitherto taken part in the etiology of but a small number of diseases in human beings. Perhaps the future will show that they occupy a larger field of activity. In a number of infectious discases whose exciting agents are as yet unknown, animal parasites are believed to have been observed-as, for example, in whooping cough, in carcinoma, and they have been apparently found as the cause in smallpox. The connection of disease with the lowest forms of animal life has, however, been established with certainty only for two affections-namely, dysentery and malaria. Dysentery. The cause of dysentery (amebic enteritis) was recognized by Losch, in 1871, as peculiar animal parasites belonging to the class of protozoa-ameba-which were found in dysenteric stools. Many other observers have since studied this organism carefully and confirmed its etiological relation to dysentery. Abscess of the Liver.-Abscess of the liver, which occurs so frequently in tropical regions, has long been associated clinically with dysentery. It has mostly been considered as a sequel of the latter disease, and although a condition needing surgical interference comes under our category. As a matter of fact, the pus and the abscess-membrane in cases of tropical abscess of the liver almost invariably contain the same amebæ that cause dysentery. Malaria. It is due to the elaborate study of malaria by Laveran that we are indebted for the discovery of the cause of that disease in 1880. The parasites of malaria are unicellular formş of life that at an early stage are endowed with ameboid movement. They belong to the class of protozoa, but there is no unanimity of opinion with regard to their position in the zoologic scale. The designation malarial plasmodia, proposed by Marchiafava and Celli, is appropriate. The parasites appear in part free in the blood-plasma, and in part in association with the red blood corpuscles. Besides the diseases mentioned above due to bacteria or to the protozoa, we have certain classes of diseases which have been designated mycoses, the etiology of which is concerned with the moulds (filamentous fungi and the budding fungi). Etiology of Mycoses.-The etiology of the diseases in human beings induced by filamentous and budding fungi has been determined by the careful studies of bacteriologists. Among these diseases we have the dermatomycoses, which include favus, herpes tonsurans, pityriasis versicolor and erythrasma. Psoriasis was once included on the list, but its supposed excitant, the epidermis phyton, has been recognized as a factitious product (Ries). Favus.-The cause of favus was recognized as early as 1839, by Schönlein, as a filamentous fungus, which, in his honor, has |