64 Veterinary Medicine. 



was given to each animal. Of 1,923 cases treated (1897-8) 30 per 

 cent, died, and 70 per cent, recovered. Of 3,197 in abandoned 

 herds (checks), 81.24 per cent, were lost. (De Schweinitz). 



One drawback was found in the short period of immunity- 

 secured, the susceptibility reappearing as soon as the antitoxin, 

 had been eliminated from the body. This was met in part hy 

 using sterilized cultures (toxins) along with the serum. 



The use of antitoxins is essentially therapeutic and cannot be 

 expected to have more than a transient action on the microbe and 

 toxins. The introduction of toxins is logical because these would, 

 naturally solicit and secure an encreased permanent production, 

 of antitoxins, etc., by the body cells. But the toxins produced 

 by the B. Cholercs Sius in artificial cultures have failed to es- 

 tablish a satisfactory immunity, and this failure is now explained 

 by the evidence that the fundamental cause of hog cholera is not 

 the B. Ch. Sius, but the invisible, infinitesimal and as yet unseen, 

 microbe. This last procures immunity, but as I noted 26 years 

 ago, so few survive, and still fewer thrive after survival, that 

 any method based on this has been eminently unsatisfactory. 

 The most obvious line of promise would be to employ minute 

 doses of the filtrate of hog cholera blood on pigs, the systems of 

 which were kept charged with antitoxins and other defensive 

 matters procured from the highly immunized body of the cow, 

 horse or other large animal. 



The fundamental objection is that it entails the preservation, 

 encrease and spread of the poison, and like all temporizing meas- 

 ures, stands as a barrier to the complete extinction of the plague. 

 Giving a protection of uncertain duration, its repetition may be 

 demanded in a few months or a year, and proceeding on the 

 ground that the pest must continue for all time, the apparent 

 economy of the process will prove, in the long run, but a perma- 

 nent and grievous tax. 



