A very important piece of evidence to show the infectiousness of rabies is the feet that the disease has almost entirely disappeared in England since the law compelling dogs to be muzzled has been rigidly enforced. When the enforcement of this law is left to local authorities it is seldom properly accomplished. The history of the disease in England and Scotland is very interesting and vain able. For several years the Board of Agriculture successfully enforced the law- in the affected districts and the number of cases was much diminished, but, when each district managed its own affairs and respected too much the indi vidual rights, the number of cases enor mously increased to 672 in 1895. The Board of Agriculture again took charge and the number of cases has steadily decreased, so that only 6 occurred in Scotland and England during 1899 and none in 1900. D. E. Salmon (Medical Record, Nov. 23, 1901).
—Rabies is al ways communicated to man by inocula tion from bites of animals suffering from the malady.
A bite of a rabid dog will produce hydrophobia in man, but the hydro phobic man does not reproduce it in others. Rabies may be continued from dog to dog, but not hydrophobia from man to man. William T. Walker (Va. Med. Monthly, Feb., '96).
It is a disease now rarely seen in America and in Germany, but it is somewhat more frequent in Russia and France. It was common in Europe some decades ago, but of recent years has been markedly less frequent. In the United States most of the cases during the last half-century have been reported from the Atlantic States. There was one out break of rabies in Ohio in 1S10. Several instances of the disease's having been communicated to man by the bites of skunks have been reported from western States. Dulles, from 1888 to 1894, col lected accounts of seventy-eight cases of hydrophobia, this number doubtless rep resenting nearly all which occurred in this country during that period.
Pathology.—The affection is, as above indicated, a specific toxtemia of un known bacterial origin. Some morbid anatomical changes in the nervous sys tem are nearly always found, these be ing: dilatation of capillaries and small blood-vessels; marked congestion, with accumulation of lymphoid cells in the perivascular spaces; minute extravasa tions of blood, and some degenerative changes in the ganglion-cells. These alterations have been noted in the brain cortex, medulla, and spinal cord; and by Gowers are alleged to be most pro nounced in the medulla and the region of the nuclei of the pneumogastric, hypo glossal, and spinal accessory nerves, the leucocyte-like accumulation being here so prominent as to merit the term "miliary abscess." The pathological changes in the spinal cord are usually not well marked.
The pathological anatomy of the spinal cords of rabbits and dogs that had died of rabies studied. Macroscopically hy Permmia of the meninges and congestion and points of limmorrhage in the sub stance of the cord were found in irregu larly-distributed areas. Microscopically these areas were seen to be extensively infiltrated with leucocytes along the peri vascular spaces and around nerve-cells, while there was proliferation of the en dothelium of the vessels. Atrophy and
vacuolation of the nerve-cells, leaving open spaces in the gray matter, were also observed. The nerve-fibres showed varicosity and vacuolation of the axis cylinder, with degeneration of the myelin-sheath and increase in the neu roglia. The process, as a whole, con sisted in an acute inflammation of the cord, tending to the destruction of the nervous elements and resulting in an hyperplasia of the neuroglia to replace them. Germano and Capobiauco (Ann. de l'Inst. Pasteur, Aug., '95).
In rabies, the brain, the cord, and meninges are usually congested and ecchymosed; the cord also shows small softened patches, particularly in the neighborhood of the nerves by which the virus has gained access to the central nervous system. The characteristic his tological appearances fall into two groups. The first comprises the more diffuse changes in the direction of gen eral mdema and hypermmia, which indi cate the commencement of inflamma tory changes around the blood-vessels. The lesions in the second group are more definite and localized. The blood vessels are. as a rule, dilated, and more or less extensive Memorrhages can be seen in the neighborhood of the central canal, in the floor of the fourth ventricle, and scattered through the membranes; where these are not maeroscopical, the microscope often reveals extravasated red corpuscles beside the dilated capil laries. Later on little hyaline globular masses appear in the small vessels, in the walls of which broad zones of wan dering cells are noted. The walls are often hyaline and much swelled; the endothelium also proliferates, so that many vessels are obliterated and sur rounded by thick hyaline masses. The changes are most marked in the situa tions indicated by the symptoms; that is, in the motor nuclei of the cord and medulla, in the neighborhood of the ol factory nerves, etc. The nerve-cells, par ticularly in the vagus and hypoglossal nuclei, are the next to suffer. They swell, and small hyaline bodies, sur rounded by a pale zone or by large vacuoles, appear in the vicinity of the nucleus. The pericellular space is filled with leucoeytes, which press on the nerve-cells; later on the latter become pale and their nuclei disappear. These changes are considered to be absolutely pathognomonic of rabies. A small piece of the cord of the suspected animal should be hardened in alcohol, stained next day with aniline red, and the char acteristic hyaline spots sought for. In this way a speedy and certain diagnosis has been made in over a hundred cases. Similar changes are found in the affected nerves; the salivary glands are also hypermmic, and the acini surrounded by sound cells, in which the characteristic tiny hyaline bodies are present just as in the nerve-cells. The lungs and ab dominal viscera are hyperemic. Babi's (Wiener med. Bliitt., Oct. 17, '95).