NATURE AND CAUSE OF HOG CHOLERA 



15 



Disinfectant 

 Antiformin 



Milk of lime 



Chlorid 

 of lime 



Lysol 



Dilution 



applied Result 



2.5 per cent solution Serum filtrate virus 

 killed in 2 hours. 

 Blood virus not 

 killed in two hours. 



Failed to kill in one 



hour. In other ex- 

 periments killed in 

 20 min. 



5.0 per cent solution Serum virus killed 

 in 1% hours. 



3.0 per cent solution Serum filtrate virus 

 usually killed in 1 

 hour. 



Cresol soap 



solution 3 6 per cent solution Always killed virus 



in 1 hour. 

 Cresol soap 

 solution 3 4: per cent solution Serum filtrate virus 



not killed in % 



hour. 



Cresol soap 

 solution 3.0 per cent solution Killed urine virus 



in y^ hour. 



Since a filterable virus has been incriminated as 

 the true cause of hog cholera, various investiga- 

 tors have from time to time attempted to isolate it, 

 stain it, and grow it on artificial culture media. 

 King has made an exceedingly careful study of a 

 spirochaete (Spirochaeta hyos) which to him has 

 seemed to possess etiological significance, but his 



