CONTAGIOUS BLOOD DISEASES. 



739 



Epizootic Aphtha is readily 

 transmitted to the human fam- 

 ily by the milk of diseased an- 

 imals, and also by inoculation. 

 The poison spreads with great 

 rapidity, and the disease often 

 proves a forerunner of other 

 diseases. .The records of the 

 disease date back for 200 years. 

 It was imported into Great 

 Britain in 1839, plunging, the 

 kingdom into dismay by the ' 

 rapidity with which it spread 

 from town to town. Since 

 then there have been periodical 

 outbreaks of Varying riialig- 

 nancy. 



COW-POX— VARIOLA VAC- 



cimm. 



This contagious, eruptive 

 disease occurs in all domestic p IG . 

 animals, and probably in wild 

 ones as welk It can be pro- 



Fio. 965.— Cow-pox— Variola Vaccinae, 



963. Fig. 963. Fig. 964. 



Different Forms of Teal Siphons. 



duced in cows by inocula- 

 tion from small-pox in man, 

 as a modified small-pox can 

 be produced in man by in- 

 oculation with the virus 

 from the cowl 



The renowned Jenner, ob- 

 serving that maids milking 

 cows thus affected were, ex- 

 empt from the more violent 

 forms of small-pox, after 

 careful -observation and 

 painstaking experiments, 

 succeeded in introducing 

 vaccination as a protection 

 to mankind from the terrible 

 ravage of unmodified small- 

 jjox. At the present day all 

 civilized nations rely upon it 



