72 DISEASES OF SWINE AND OTHER ANIMALS. 



accideut in contact vrith a raw snrface, will prodnce disease as snrely as 

 did the qnills in my inoculations. My own observations in tliis respect 

 liave been more than corroborated by one of Professor Axe, of the Eoyal 

 Veterinary College, London. He i^roduced the disease by inoculating- 

 from ivory points on which the cutaneous exudation had been dried up 

 for the long i^eriod of twenty-six days. 



That the poison can be in-eserved even in the liquid state when the 

 germs of pntref action are excluded, may be inferred from my successful 

 inoculations with blood that had been kept in an isolation a-i>paratus, at 

 the ordinary body temperature, for the period of eleven days. As directly 

 to the point is the cultivation of the poison in aqueous humor for seven 

 days, by ELlein, and its subsequent successful inocnlation. This experi- 

 ment of KHein is, however, possessed of vastly greater importance, inas- 

 much as by it it was first shown that the poison can be cultivated and 

 indefinitely increased out of the animal body as well as in it. On seven 

 successive days he inoculated seven successive portions of aqueous humor 

 with as much of the inoculated liquid of the previous day as would ad- 

 here to the point of a needle, the first having been similarly inoculated 

 from the sick pig. From the cultivations of the fifth and seventh days, 

 respectively, a drop was taken and two pigs were successfully inoculated 

 therewith. In the cultivation of each day were found myriads of hacillus, 

 but no other organization, and thus Klein was the first to show that the 

 hacillus is the probable cause of the disease. Had there been no repro- 

 duction and increase of the poison, it mnst have been rendered incon- 

 ceivably dilute, an approximate ratio of the poison added to the first 

 day's cultivation, and that added to the last, being about as 1 is to 

 1,000,000,000,000,000,009. That such a dilution could be operative seems 

 utterly incredible, a^nd as modern research shows that virulence resides 

 not in simple liquids, but in the solid particles contained in them, and 

 as the only definite organisms in the cultivation liquids were the hacilU, 

 it seems inevitable that these are the active canse of the disease. But 

 if so, they cannot only be ])reserved, but increased in suitable fluids out- 

 side the animal body. It is true they disappear when the active organ- 

 isms of ordinary putrefaction {hacferimn iermo) become numerous, but 

 they are not necessarily destroyed. From what we know of the life of 

 these mycrophytes it is to be feared that so far as the hacillns has ad- 

 vanced to the i^roduction of spores, it will be jireserved in a dormant 

 state, like so many dried seeds, until conditions favorable to its growth 

 shall transi)ire. On the other hand it may be recollected that my at- 

 tempts to propagate the disease from a putrefying bowel failed, so that 

 further observation is wanted before we can say that the hacillus or its 

 spores are X)reserved in a septic liquid. However that may be, the i)os- 

 sibility of its increase in a non-septic normal fluid is an additional argu- 

 ment for the total destruction of all diseased pigs and morbid products. 



In the case of high-priced pigs, where expense is no object, and where 

 the patients can be kept in thoroughly disinfected pens, mider the most 

 rigid seclusion, treatment may sometiines be commendable; but in the 

 case of common herds, and as viewed from the standpoint of the great- 

 est good to the greatest number, there can be no question at all that the 

 treatment of the sick is the most ruinous policy, while the most stringent 

 measures for the extinction of the poison is the only economical one. 

 The universal experience of veterinarians supx)orts this conclusion, and 

 nearly every European government has now reached the same conviction, 

 and absolutely ])revent the preservation and treatment of the victims of 

 those fatal contagious diseases which most threaten their flocks and 

 herds. 



