SMALL-POX. 285 



In 1593 Simon Kellwaye appended to his work on the Plague 

 a short treatise on the small-pox. " Oftentimes," he wrote, " those 

 that are infected with the plague are in the end of the disease 

 sometimes troubled with the small pocks or measels, as also by good 

 observation it hath been seen that they are fore-runners or warnings of 

 the plague to come." According to Kellwaye the disease arose from 

 the " excrements of all the foul humours in our bodies, which striving 

 with the purest doth cause a supernatural heat and ebullition of our 

 blood, always beginning with a feaver in the most part." 



Small-pox steadily increased in the seventeenth century until it was 

 a formidable scourge, for no advantage was taken of all the experi- 

 ence which had been gained in dealing with the plague. No public 

 measures were adopted to cope with the disease, and the people came 

 to regard the new pestilence as a visitation which was unavoidable. 

 Early in the eighteenth century, small-pox inoculation was introduced, 

 and this was superseded in the nineteenth century by vaccination. 



Examination of small-pox cases after death does not reveal any 

 characteristic lesions in the internal organs, but sections of small- 

 pox vesicles show an important structure. A vesicle is formed by 

 the exudation raising up the outer layer of epidermis, and the chief 

 feature is the formation of a vacuolated structure in which, especially 

 in the later stages, bacteria are found iji abundance. 



Bacteria in Small-pox. — Cohn and Weigert found cocci in 

 variolous lymph. Hlava found Streptococcus pyogenes in the pustules, 

 and Garre streptococci in the internal organs in a case of variola 

 haemorrhagica. In a fatal case of variola complicated with pemphigus 

 Garr6 found a streptococcus in the pemphigus vesicles. Klein 

 and Copeman have found a small bacillus which they regard as 

 characteristic, but its biological characters are unknown, as it will 

 not grow on any nutrient media. The bacteria commonly found in 

 variolous pus are the usual pyogenic organisms. The nature of 

 the contagium of small-pox is unknown. 



Protective Inoculation. — Experience had taught that a person 

 was not, as a rule, attacked with small-pox a second time ; but when 

 and how the method of artificially inducing a mild form of the 

 disease was discovered, or when this preventive treatment was first 

 employed, is unknown. Avicenna of Bokhara was credited with the 

 discovery, and it was supposed that the practice was carried by 

 Tartar and Chinese traders to Surat, Bengal, and China, and by 

 the Mahommedan pilgrims to Mecca. In Constantinople it was 

 supposed by some to have been introduced from thiC Morea by 

 an old woman, and by others by the women of Oircassia. The 



