60 MURRAIN ing it. Quite recently, Semmer of the Dorpat veterinary school has made experiments with cultivated or attenuated virus, and so far the results have been encouraging. 3. Pleuro-Pneumonia or Lung -Plague. The next murrain in importance, with regard to destructiveness, is the so-called "lung-plague" or contagious "pleuro-pneumonia" of cattle. This disease is particularly interesting from the fact that within less than two centuries it has been spread from a very small area over nearly every part of the world. The earliest notices of it testify that it first prevailed in central Europe, and in the last century it was present in certain parts of southern Germany, Switzerland, and France, and had also appeared in upper Italy. Though Valentine described an epizooty occurring among cattle in 1693 in Hesse, yet doubts have been entertained as to whether it was this malady. It was not until 1769 that it was definitely described as prevailing in Franche-Comte by the name of "murie." From that date down to 1789 it appears to have remained more or less limited to the Swiss mountains, the Jura, Dauphine , the Vosges, Pied mont, and upper Silesia ; it showed itself in Champagne and Bourbonnais about the time of the Revolution, when its spread was greatly accelerated by the wars that followed, and the consequent demand for cattle for the commissariat parks of the contending armies. Since that time the continually increasing commercial relations be tween various countries have carried it to the ends of the earth, the long duration of latency, and the some what slow course of the disorder, eminently adapting it for conveyance to great distances. In this century its diffusion has been accurately determined. It invaded Prussia in 1802, and soon spread over North Germany. It was first described as existing in Russia in 1824; it reached Belgium in 1827, Holland in 1833, the United Kingdom in 1841, Sweden in 1847, Denmark in 1848, Finland in 1850, South Africa in 1854, the United States Brooklyn in 1843, New Jersey in 1847, Brooklyn again in 1850, and Boston in 1850; it was also carried to Melbourne in 1858, and to New South Wales in 1860; New Zealand received it early in 1864. It has also been carried to Asia Minor, and has made its presence felt at Damascus. In Austria it is less prevalent than in some other European countries, being scarcely known except in Bohemia, Moravia, and a portion of Tyrol. In Hungary it appears to be almost unknown, in consequence of the minimum importation of foreign cattle; and in countries to which it has not been introduced by infected animals it is not seen. In consequence of its insidious invasion, the subtlety of its contagion, and the great fatality attending it, there can be no doubt that it is one of the most disas trous plagues that can afflict a cattle-producing country. Fortunately, unlike the two preceding murrains, it is con fined entirely to the bovine species ; no well-authenticated instances of its transmission, either accidental or experi mental, to other species have been recorded. In its nature it is a specific infectious disease, generally affecting the lungs and the lining membrane of the chest, producing a particular form of lobar or lobular pleuro- pneumonia, and in the majority of cases, if not in all, it is transmitted through the medium of the inspired air, hence its localization in the lungs. Inoculation with the fluid from the diseased lungs does not produce any effect on other than the bovine species ; but in this its action is most energetic. Producing, after a certain interval, char acteristic lesions at the seat of inoculation, the morbid change or infective process soon involves parts beyond, and if not checked may cause most serious damage and even the death of the inoculated animal; though it does not develop the lung lesions always observed in accidental in fection, yet there is a local anatomical similarity or identity. Symptoms. The malady is slow and insidious in its course, last ing from two to three weeks to as many months, the chief symptoms being fever, diminished appetite, a short cough of a peculiar and pathognomonic character, with quickened breathing and pulse, and physical indications of lung and chest disease. The progress of the malady is marked by exacerbation of the symptoms, and towards the end there is great debility and emaciation, death generally en suing after hectic fever has set in. liecovery is somewhat rare. The pathological changes are generally limited to the chest and its contents, and consist in a peculiar marbled-like appearance of the lungs on section, and fibrinous deposits on the pleural mem brane, with oftentimes great effusion into the cavity of the thorax. Willems of Hasselt (Belgium) in 1852 introduced and practised inoculation as a protective measure for this scourge, employing for this purpose the serum obtained from a diseased lung ; and his suc cess was so marked that he made known his procedure. Since that time inoculation has been extensively resorted to, not only in Europe, but also in Australia and South Africa ; and its protective value has been generally recognized. When properly performed, and when certain precautions are adopted, it would appear to confer immunity from the disease. The usual seat of inoculation is the extremity of the tail, the virus being introduced beneath the skin by means of a syringe or a worsted thread impregnated with the serum. One or two drops are sufficient to cause the local and constitutional disturbance which mark successful prophylactic infection. A par ticular micro-organism has been discovered in the diseased textures and iluids of animals affected with contagious pleuro-pneumonia, which is supposed to cause the malady. It has been cultivated, and inoculation experiments have been made with it. The intra venous injection of the virus has been found to be a safer method of conferring immunity than inoculation beneath the skin, and quite as certain a method. 4. Foot- and- Mouth Disease (Epizootic Aphtha, Eczema epizootica), if we were to judge by the somewhat vague descriptions of different disorders by Greek and Roman writers, has been a European malady for more than 2000 years. But no reliance can be placed on this evidence, and it is not until we reach the 17th and 18th cen turies that we can find trustworthy proof of its presence, when it was reported as frequently prevailing extensively in Germany, Italy, and France. During this century, owing to the vastly-extended commercial relations between every civilized country, it has, like the lung-plague, become widely diffused. In the Old World its effects are now experienced from the Caspian Sea to the Atlantic Ocean. It gradually extended towards Britain at the commence ment of this century, after invading Holland and Belgium, and about 1839 appeared in England, where it was imme diately recognized as a new disease ; it quickly spread over the three kingdoms. From the observations of the best authorities it would appear to be an altogether exotic malady in the west of Europe, always invading it from the east ; at least, this has been the course noted in all the principal invasions. It was introduced into Denmark in 1841, and into the United States of America from Canada, where it had been carried by diseased cattle from England. It rapidly extended through cattle traffic from the State first invaded to adjoining States, but was extinguished, and does not now appear to be known on the American continent. It was twice introduced into Australia in 1872, but was stamped out on each occasion. It appears to be well known in India, Ceylon, Bunnah, and the Straits Settlements. In 1870 it was introduced into the Andaman Islands, where it had not previously been seen, by cattle imported from Calcutta, where it was then prevailing. There is evidence that it is common in South Africa, and is frequently epizootic there, causing great inconvenience, owing to the bullocks used for draught purposes, which travel great distances, becoming unfit for work, by which traffic is much interfered with. These cattle also spread the contagion. It is not improbable that it also prevails in Central Africa, as Schweinfurth alludes to the cattle of the Dinkas suffering from a disease of the kind. Though not a fatal malady, and in the majority of cases readily amenable to treatment, yet it is a most serious scourge. It is transmissible to nearly all the
