Thucydides says that no one was attacked a second time, or if he were the result was not fatal. Immunity of this kind, comparatively complete, is alike characteristic of typhus and plague: the question is one that has provoked considerable controversy right down to modern times. Both Curschmann and Murchison are agreed as to the extreme rarity of relapses and reinfections in typhus: curiously, Murchison himself had two typical severe attacks. In the case of plague, Alexander Massaria,[214] from his experience at Vicenza, came to the conclusion that one attack rendered a man immune with very few exceptions, but that a second attack might be mortal. Mercurialis and Van Helmont were in agreement as to the rarity of second attacks. Diemerbroeck[215] recorded two cases of reinfection in the same year of the plague at Nymwegen, and several cases at an interval of a few years. During the plague of Marseilles in 1720, various writers observed cases of reinfection, and relapse was also said to be frequent. In the plague of 1771 at Moscow, Samilowitz, prejudiced by his own advocacy of inoculation, denied the existence of reinfection, and suffered retribution for his dogmatism by three relapses in his own person. In the same plague both Mertens and Orraeus recorded cases of reinfection. In the plague of Aleppo, Russell noted 28 cases of reinfection within three years among 4,400 victims of plague. Thus the idea of complete immunity, so prevalent popularly both in Europe and the Levant, must be accepted with some reservation. OXFORD: HORACE HART M.A. PRINTER TO THE UNIVERSITY FOOTNOTES: [200] Curschmann’s contribution, in Nothnagel’s _Encyclopaedia of Practical Medicine_, is perhaps the most graphic and succinct account of Typhus Fever in modern medical literature. The record of Thucydides should be studied closely side by side with this. Murchison’s article, in his _Treatise on Continued Fever_, though admirable, is so diffuse as to make comparison difficult. [201] _Iliad_ ii. 723. [202] _Iliad_ viii. 405 and 419. [203] _Adonis_, 16-17. [204] _Agamemnon_, 645. [205] _Antigone_, 652. [206] _On Ancient Medicine_, § 16. [207] _Coacae Praenotiones_, § 396. [208] _Frogs_, 236. [209] _Wasps_, 1119. [210] _Ecclesiazusae_, 1057. [211] _Epidemics_, iii. [212] xli. 21. [213] _Obs._ p. 870. [214] _Tract. de Peste_, ed. 1669, p. 509. [215] _De Peste_, Lib. IV. Hist. 37. 45.