Causes of Mild or Severe Smallpox.
Besides the errors of the heating or the cooling regimen respectively, there is another thing that may have had something to do with the greater fatality of smallpox, as remarked by many, about the middle of the 17th century. “How is it,” asks Sydenham, “that so few of the common people die of this disease compared with the numbers that perish by it among the rich[845]?” Sydenham may not have known how much smallpox mortality there was in the poorer quarters of London. But the Restoration was certainly a great time of free living in the upper classes of society, and it is equally certain that smallpox was apt to prove a deadly disease to a broken constitution. Willis believed that excesses even predisposed people to take the infection: “I have known some to have fallen into this disease from a surfeit or immoderate exercise, when none besides in the whole country about hath been sick of it.” There were, of course, families in which smallpox was for some unknown reason peculiarly fatal. Again, the origins of constitutional weakness are lost in ancestry, the poor stamina of children being often determined by the lives of their grandfathers or great-grandfathers. In the royal family of Stuart smallpox proved more than ordinarily fatal, but it was among the grand-children and great grand-children of James I. that those fatalities happened. Of the children of Charles I., the Duke of Gloucester and the Princess of Orange died of smallpox within a few months of each other in the year of the Restoration. The disease was not less fatal a generation after in the family of the Duke of York (James II.). Dr Willis fell into disgrace with that prince because he bluntly told him that the ailment of one of his sons was “mala stamina vitae.” All his sons, says Burnet, died young and unhealthy, one of them by smallpox. Of his two daughters, Queen Mary died of haemorrhagic smallpox in 1694, and the Duke of Gloucester, only child of the other, Princess Anne of Denmark (afterwards Queen Anne), died at the age of eleven, of a malady which was called smallpox by some, and malignant sore-throat by others[846].
Among the medical writers of this period, who gave reasons why smallpox should be so severe or deadly in some while it was so slight in others, Morton was the most systematic. He made three degrees of smallpox—benign, medium and malignant: these did not answer quite to the discrete, confluent and haemorrhagic of other classifiers, for his malignant class included so many confluent cases that in one place he uses malignae as the equivalent of confluentes seu cohaerentes, while his middle class was made up of some confluent cases,—perhaps such medium cases as had confluent pocks on the face but not elsewhere,—and a certain proportion of discrete. The medium kind were the most common (frequentissimae sunt et maxime vulgares variolae mediae). Still, it was the benign type that he made the norma or standard of smallpox, from which the disease was “deflected” towards the medium type, or still farther deflected towards the malignant. He gives a list of fourteen things that may serve to deflect an attack of smallpox from the norma of mildness to the degrees of mean severity or malignity:
1. If the eruption come out too soon or too late.
2. If the patient be sprung from a stock in which smallpox is wont to prove fatal, as if by hereditary right.
3. If the attack fall in the flower of life, when the spirits are keener and more inclined to febrile heats.
4. If the patient be harassed by fever, or by sorrow, love or any other passion of the mind.
5. If the patient be given to spirituous liquors, vehement exercise or anything else of the kind that tends to irritate the spirits.
6. If the attack come upon women during certain states of health peculiar to them.
7. If cathartics, emetics and blooding had been used.