318 PROTECTIVE INOCULATIONS. 



precautions are taken in giving these injections, and a little absorbent 

 cotton is placed over the puncture. 



FOOT-AND-MOUTH DISEASE. 



This is an infectious disease of cattle, sheep, goats, and swine, the 

 etiology of which, so far as the specific infectious agent is concerned, 

 has not been determined. 



The extent to which the disease in question prevails in some parts 

 of Europe is shown by the statistics for 1891 of the prevalence of this 

 disease in Germany. According to the Eeichsseuchenbericht it pre- 

 vailed most extensively in the southern portion of Germany. The 

 total number of infected farms was 47,865; the total number of in- 

 fected cattle was 394,640; of sheep, 240,904; of goats, 3,378; of swine, 

 182,208. Behla (1892) has made inoculation experiments with the 

 filtered saliva of infected cattle to which he added one to two per cent 

 of carbolic acid, and claims to have produced immunity in young pigs 

 and lambs. The duration is not, however, very long even in animals 

 which have recovered from an attack of the disease said to be from 

 six months to three years and a practical method of restricting the 

 disease by means of protective inoculations has not as yet been intro- 

 duced. 



GLANDERS. 



The toxic substances produced in cultures of the glanders bacillus 

 when concentrated in the form of a glycerin extract constitute the so- 

 called mallein, which has been extensively used in the diagnosis of 

 glanders in horses. As is the case when animals infected with tuber- 

 culosis are inoculated with tuberculin, animals infected with glanders 

 have a decided rise of temperature after receiving a sufficient dose of 

 mallein beneath the skin. 



Babes (1892) reports that the toxic substance in cultures of the 

 glanders bacillus may be obtained by precipitation with alcohol; and 

 that mallein obtained from filtered cultures to which glycerin has 

 been added, or the alcoholic precipitate, may be successfully used 

 for protecting susceptible animals against glanders infection or for 

 curing the disease after infection. He has demonstrated the thera- 

 peutic value upon guinea-pigs and upon two horses which are said to 

 have been cured of chronic glanders. When large and repeated doses 

 are injected into healthy animals they produce nephritis and general 

 marasmus. The action upon horses infected with glanders is very 

 marked and small doses may even cause death. 



Kresling (1892) recommends potato cultures as preferable to bouil- 



