1849. After the subsidence of the great epidemic of relapsing and typhus

fevers (1847-49), says Dr Dennis O’Connor, of Cork, “intermittent fever made its appearance, and, as long as it lasted, scarcely a case of continued fever was seen. As soon as the last cases of intermittent disappeared, the present epidemic broke out (1864-65), and still rages with much severity. This alternation of continued and intermittent fever is remarkable. Indeed it might have been observed that the fever of 1847 passed first into a remittent form, and gradually into the intermittent which prevailed more or less for ten years subsequently[527].” The same succession of relapsing fever by intermittent fever was observed after the epidemic of 1826 by Dr John O’Brien, of Dublin[528]. The epidemic of fever which Dr O’Connor describes for Cork in 1864-65, appeared in Dublin about the same time--the latter half of 1864. It was of the nature of typhus in both cities, cerebro-spinal in part, but probably not typhoid[529]. At Cork it had some peculiarities--a croupous-like exudation on the tongue, resembling thrush in the mouth, and a dark mottled rash (rubeola nigra), or fiery red spots on a dark red ill-defined base. “The true typhoid rash has been seen but seldom, and the petechiae of genuine typhus, so frequent in former epidemics, have been equally rare. The latter I attribute to the improved condition of our poor in good clothing and the ventilation of their dwellings.” The intellect was little disturbed in this fever, there was usually a crisis about the fourteenth day, and there were no relapses. The sequelae were peculiar--“great nervous debility, leading to a semi-paralysed state of the limbs,” congestion of the lungs, sometimes solidification, or gangrene or suppuration of them. It occurred at a time “when the food of the people is most abundant and of the best quality.” There had been three bad harvests in succession from 1860, but it may be inferred from a Dublin article of August, 1863, that no epidemic of typhus had arisen in Ireland down to that date, although there was much typhus in England, especially in Lancashire owing to the “cotton famine.” When the epidemic did arise in Dublin, Cork, and doubtless elsewhere in Ireland, in the latter part of 1864, to continue throughout 1865, it was not connected with scarcity or distress among the common people. On the other hand, Dr Grimshaw, of Dublin, found that it was subject to influences of the weather, as if the infective principle had been a soil poison like that of plague, yellow fever, cholera, or enteric fever. Taking the Cork Street Fever Hospital for his study, he made out that there was a very close correspondence, from the 29th of May to the 31st of December, 1864, between the fluctuating pressure upon its accommodation and the periodic rises in the atmospheric moisture and heat, the crowd of patients being always greater when a high temperature coincided with a large rainfall[530]. One would not have been surprised to find some such law as that in enteric or typhoid fever, although a correspondence from day to day is subject to many sources of fallacy; but, by all accounts, the disease was typhus, the last of the considerable outbreaks of it in Ireland hitherto, and an outbreak that seemed to require, both at Cork and Dublin, the language of Sydenham’s epidemic constitutions for its adequate description. For a good many years, the continued fever of Dublin has been chiefly enteric or typhoid. As late as 1862 a physician to the Fever Hospital, unconvinced by the method of Sir William Jenner, believed that he observed a transition from the old typhus into the new enteric: “The change at first seemed to be to the gastric type; to which was shortly added diarrhoea in nearly every instance; and this latter, again, occurring in a large number of cases which presented all the characters of typhus, including a dense crop of petechiae[531].” Assuming that there had been a mixture of cases of enteric and typhus fevers, the latter must have had diarrhoea among the symptoms, as they often had in special circumstances (as well as tympanitis). Since that time the species of typhus has greatly declined, and the species of typhoid has considerably increased. The remodelling which Dublin has undergone, like all other old cities, explains the one fact. The notorious Liberties have been in great part rebuilt, and the conditions of typhus, as well as its actual fomites, to that extent removed. On the other hand, something has happened to encourage the soil poison of enteric fever. It is not easy to say what are the conditions that have favoured the enteric poison in modern towns; but there can be little doubt about the fact in general, or that Dublin and Belfast are among the best fields for the study of the problem[532].