In all epidemics which increase to such a degree as to become contagious, it is of importance to distinguish which of these causes are the more powerful, the predisposing or epidemic causes, which originate the proneness to the disease, or the proximate causes, among which, in the generality of cases, contagion is the most prominent. The predisposing were here evidently the more operative; contagion was not added till the disease was at its height, and although it contributed not a little to its spread, yet it always remained subordinate to the other sources of the disease, and all the matter of infection vanished without a trace, on the cessation of the disorder, so that the subsequent eruptions of it were always produced by the renewal of those general causes which are in operation upon and under the earth. It is, however, as little within the compass of human knowledge to discover the essential foundation of this renewal, as the proximate causes of the appearance of the mould spots at the commencement of the sixteenth century, or any other of those processes which are prepared and brought into activity by the hidden powers of nature. SECT. 6.—INFLUENZAS. Several epidemics thus originating in causes beyond human comprehension appeared in the 16th century. Among the most remarkable was a violent and extensive catarrhal fever in 1510, of that kind which the Italians call Influenza, thus recognising an inscrutable influence which affects numberless persons at the same time. It prevailed principally in France, but probably also over the rest of Europe, of which, however, the accounts do not inform us, for in those times they took little pains to record the particulars of epidemics which were not of a character to affect life. According to recent experience we should be warranted even in supposing that this malady had its origin in the remotest parts of the East. During the whole of the winter, which was very cold, violent storms of wind prevailed, and the north and middle of Italy were shaken by frequent earthquakes; whereupon there followed so general a sickness in France, that we are assured by the historians that few of the inhabitants escaped it. The catarrhal symptoms, which on the appearance of disorders of this kind usually form their commencement, seem to have been quite thrown into the background by those of violent rheumatism and inflammation. The patient was first seized with giddiness and severe headache; then came on a shooting pain through the shoulders, and extending to the thighs. The loins too were affected with intolerably painful dartings, during which an inflammatory fever set in with delirium and violent excitement. In some the parotid glands became inflamed, and even the digestive organs participated in the deep-rooted malady; for those affected had, together with constant oppression at the stomach, a great loathing for all animal food, and a dislike even to wine. Among the poor as well as