VACCINATION. IMMUNIZATION. INOCULATION 241 



exposed to the disease. According to Piitz, the number of animals affected 

 with lung plague in Holland was reduced by vaccination from 6079 in 1871 

 to 2227 in 1875, 951 in 1877, 157 m 1879 and, finaUy, 11 m 1882. In Hasselt, 

 where 200,000 cattle were vaccinated with good results during the period 

 from 1850 to 1880, the losses regularly increased when vaccination was omitted. 

 Rochebrune relates that for years the Moors in Senegambia have vaccinated 

 their cattle against limg plague with good results by sticking the point of a 

 knife into the lungs of a slaughtered animal and then incising with the knife 

 the skin of the animal to be vaccinated in the region of the nostrils. 



The opponents of vaccination point out that a positive case of immuniza- 

 tion by vaccination has not been demonstrated up to this time. Even the 

 friends of vaccination are not in a position to state how long the immunity 

 continues, whether % or 1 or 2 years; others who favor vaccination speak 

 only of partial action and immunization and therefore vaccinate several times. 

 The specific character of the vaccination swelling is disputed, since an entirely 

 similar swelling arises after the inoculation of pus or milk. Furthermore, the 

 vaccination has in no case produced a lung plague pneumonia, the principal 

 criterion of the disease, while this alteration occurs even in those cases in 

 which the infection is transmitted intra-uterine from the mother to the foetus. 

 The results of vaccination are dependent upon the method and time of inocu- 

 lation and upon the quaUty of the vaccine. Animals already immune were 

 also frequently vaccinated and the previously acquired immunity attributed to 

 the effects of the vaccine. The disease has been introduced and artificiallyprop- 

 agated by vaccination. The losses from vaccination are under certain circum- 

 stances very considerable; the mortality is frequently very great, even at times 

 exceeding the usual f atahties from the disease itself. In the preamble to the 

 German Imperial veterinary sanitary laws thelosses from vaccination are given 

 as 2 to 4 per cent. ; the end of the tail is lost in 25 per cent, of thecases according 

 to the observations of a French vaccination commission, in 10 to 15 per cent, 

 according to Degive. In addition there are the economical disadvantages, 

 decrease of the milk secretions, emaciation, etc. The disease often spreads 

 in spite of vaccination, while in other cases it subsides without vaccination; 

 many animals have the disease without showing perceptible symptoms. In 

 those countries in which vaccination was most extensively practised the 

 disease is not yet on the decUne. In England, for example, and in France and 

 Belgium, in which vaccination was obhgatory, as well as in the province of 

 Saxony, the disease still exists. In other countries, for instance Holland, the 

 repression of the disease is perhaps not the result of vaccination but of the 

 simultaneous enforcement of veterinary police measures, especially slaughter. 

 In Belgium, according to Oemler, the number of cases of lung plague increased 

 from 1481 in 1867 to 2800 in 1878 in spite of vaccination, but after that date, 

 16 



