The above are the essential symptoms of small-pox, both in the distinct and confluent form. This disease is, however, often accompanied by other symptoms, which we have merely space to name; such as sore throat (which often depends upon pustules situated there), salivation, and (in the confluent form, during the secondary feveil crysipelatous inflammation, leadinn.sloughingto the formation of abscesses, glandular swellings, sloughing sores on the sacrum, etc. In pregnant women, the disease often' causes abortion, which is most commonly followed by death. The dead child occasionally, but not often, is covered with pustules.
The cause of small-pox is universally allowed to be a specific contagion, of whose nature we are in the most profound ignorance. There is probably no disease so contagious as till's. Dr. Haygarth stated (in 1793) that, during his long attention to this subject, not a single instance has occured to prove that persons liable to small-pox could associate in the nme chamber with a patient in the distemper without receiving the infection; and he was informed by an American physician of an instance in which the poisonous effluvium crossed a river Iwo feet wide, and affected 10 out of 12 carpenters who were working on the other side. The contagion acts either through the air, or by contact with the skin, or by inoculation; and the disease may he caused by the dead body, even when it has not been touched. What products of the diseased body are contagious Is not exactly known, but the contents of the pustules and the dried scabs certainly are so. Opinions are divided as to the period at which the disease begins and ceases to be contagious. It is safest to maintain that it is capable of self-propagation as soon as the febrile symp toms have exhibited themselves. How soon the patient ceases to be dangerous, cannot be decided with accuracy; but the stability of the contagious principle may be inferred from the fact, that clothing will retain it for months, and it is said for years, when con. Like all the contagious exanthemata, small-pox appears in an epidemic form, at irregular, and, in our ignorance, it would almost seem capricious intervals. After an extraordinary exemption, perhaps for years, a district is suddenly invaded by it, and *continues to suffer for a longer or shorter period, after which the disease spontaneously disappears—dies out, as it were—and does not reappear perhaps for years. Different •epidemics vary very much in their severity, and isolated cases are usually milder than those occurring when the disease is epidemic. Race has nitwit to do with the severity of the disease; the constitution of the dark races, the negro and the red Indian, being sin of the contagion, and exhibiting very little power of resisting the fatal tendency of the disease. It is universally admitted that the discovery of vaccination (q.v.), by which small-pox deprived of its danger, is the greatest triumph of modern medicine. Inoculatton (q.v.) protected the individual, but increased rather than diminished the total number' of deaths, while vaccination has the advantage of protecting both the individual and the community. Although, in the great majority of cases, vaccination affords perfect pro tection against small-pox, it not very unfrequently happens that vaccinated persons, when exposed to the contagion of small-pox, get the disease in a modified form, milder and shorter even than after inoculation, and therefore incomparably milder than in the natural form. The disorder occurring under these circumstances has received the various names of modified or small-pox, or the varioloid disease. As Dr. Wood observes: "It is impossible to describe minutely all the shapes which the vario loid disease assumes. There is every shade between the slightest symptoms, scarcely recognizable as having affinity with small-pox, and the nearest possible approach to‘the regular disease."—Pracike of Medicine, 4th ed., vol. i., p. 380. In whatever form the varioloid disease appears, it wants the peculiar odor of small-pox, and secondary fever is very rare. The constitutional disturbance which, for the first week, may have been as severe as in the disease, usually subsides entirely when the eruption has reached its height, and the patient is convalescent at the period when, if he had not been vaceivated, he would have been in the greatest danger.
With regard to prognosis, it may be stated generally, it is a very fatal, and was formerly an extremely destructive disease—one death occurring in every four cases. Modified small-pox is very seldom fatal, although instances of death are occasionally reported. Small-pox is more fatal at the two extremes of life than in the intervening period, and, as has been already noticed, is especially dangerous iu pregnancy. In olden
times, it was believed that the eruption was an effort of nature to get rid of the noxious matter, and hence heating and stimulating measures were adopted with the view of pro moting the eruption. To Sydenham (q.v.) belongs the credit of first recommending an entirely opposite or cooling mode of treatment: but his suggestions met with the most severe opposition, and it was not till long after his death that the cooling treatment was fairly established. In mild cases, and in cases of varioloid disease, the physician has merely to guard the patient against hurtful influences, such as stimulating foods or drinks, too hot a room, or improper exposure to cold, and to prescribe cooling drinks during the fever, and occasional laxatives if they shall be required. In more severe cases, the fever may be combated by saline purgatlyes, prescribed so as to produce two or three liquid stools daily, and by free ventilation of the surface of the body. When the eruption is all out, if the pimples on the face are few and distinct, the danger may be _regarded as over, and no further treatment is required. If, however, the disease assume a confluent form, wakefulness and restlessness are apt to come on about the eighth day, and opiates in free doses may be prescribed with benefit. If the pustules are abnormally torpid in reaching their maturity, it may be expedient to administer strong broths, or even wine; and when the pustules are livid, and intermixed with peteechim (q.v.), bark and acids must then be additionally ordered, although the patient is then too often beyond the reach of help. During the secondary fever, the bowels must be kept gently open, and opiates should be prescribed once or twice each day. A. more nourishing diet is now called for, and wine should be given if the pulse is very weak. The external itching is partly relieved by the opiates, but local applications are also employed: cold cream, or a mixture of equal parts of olive oil and lime-water, may be this used with advantage. Special methods have been devised for the purpose of preventing the pitting or seaming of the face, which is often a hideous permanent dis figurement of the patient. The best application of this kind is probably that of nitrate of silver. Mr. Iligginbottom, who first suggested this application, touched each dis tinct papula with a solid stick of lunar caustic, previously moistened; but when the spots were confluent, lie washed the whole face, about the third day after the eruption, with a strong solution of this salt, containing eight scruples to the ounce of water. In the Paris hospitals, various mercurial preparations are employed, which are said to cause the pustules to abort. M. Briquet recommends mercurial ointment, simply thick ened with powdered starch. Dr. Wood of Philadelphia remarks, that as the ointment sometimes salivates, it should be diluted with an equal quantity of lard before the starch is added. Prof. Bennett of Edinburgh recommends the application of calamine (carbon ate of zinc) mixed with olive oil; it forms a coherent crust, and thus excludes the air.
During the period of desquamation, an occasional warm bath may be prescribed with advantage; and the patient should always resort to this measure, as a precaution against carrying the contagion about with him, before again mixing in society.
The history of this remarkable disease is clothed in considerable obscurity. There is no evidence that it was known to the Greek or Arabian writers of the 6th c., and the first accurate description of it is that of Rhazes, an Arabian physician, who flourished early in the 10th century. It appears to have reached England toward the close of the 0th c. After the crusades it prevailed in most of the temperate countries of Europe, but did not reach the northern countries of Norway, Lapland. etc., for some time.later. In 1517 it was carried from Europe to St. Domingo: and three years later, it reached Mexico, where it committed fearful devastations, and whence it spread with intense virulence through out the new world. (According to Robertson, three millions and a half of people were destroyed in Mexico alone.) In 1707. it was introduced into Iceland, when more than a fourth part of the whole population fell victims to it; and it reached Greenland still la ter (in 1733), when it spread so fatally as almost to depopulate the country. These cases are striking illustrations of the law that seems universally true, that a contagious dis ease is always most virulent on its first introduction to a new scene of action.