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Bacteriology 



the sickness. Bacteria give off waste products much the same as animals 

 do, these waste products may become so rancid to the bacteria that it is 

 the cause of their death and hence the disease ends. In cream lactic acid 

 bacteria live till the cream sours and then they die and then the puterifying 

 bacteria find suitable food and they thrive a few days and the food be- 

 comes so poisonous that they too die. 



The poisonous products which bacteria give off are called toxins 

 and in every bacterial disease the effected animal throws off an anti-toxin 

 or medicine to counteract or neutralize the effect of the toxins of the bac- 

 teria. That is the sick animal's body manufactures the anti-toins. In every 

 disease the anti-toxin is of different composition. That is the anti-toxin 

 of hog cholrea or anti-hog cholrea serum has no effect on pneumonia 

 bacteria but if properly made and administered it prevents hog cholera. 

 That is hog cholrea germs can not develop in its presence. A hog may 

 be able to manufacture sufficent anti-toxin to recover from hog cholrea 

 (in rare cases) if they don't recover it is generally supposed that the 

 bacteria develop poisons faster than the hog can develop anti-toxin to 

 neutralize the effect of the poison of the bacteria. 



Man has not been able to develop elements of a composition that 

 will kill the bacteria of many diseases without killing the patient, how- 

 ever man can develop through animals bacterial products that protect 

 healthy animals. 



In the vaccination of calves to prevent black-leg and anywhere a 

 vaccine is used we inject into the animal's body weakened germs of the 

 disease. These germs are usually weakened by heating to a definite tem- 

 perature. As soon as these germs are placed beneath the skin they begin 

 to multiply but not so rapidly as healthy germs, hence the animal has 

 sufficient time to manufacture enough anti-toxin to neutralize their poisons, 

 or kill the germs. This causes the calf to fill his blood with the anti- 

 toxin and the animal is able to resist black-leg. 



There are bacterins injected for the prevention or cure of many 

 diseases. Bacterins are made for poll-evil, fistula etc. and are called 

 polavalent bacterins. The pus is taken from a fistula and grown in 

 an especially pjepared beef broth for a number of hours, while in the 

 beef broth the bacteria throw off their poisonous products after which 

 they are killed. Then a small amount of the broth is injected under the 

 skin of the horse and as soon as this happens the horse is supposed to 

 go to work to manufacturing an anti-toxin to counteract the poison even 

 though no bacteria are injected. By the horse making sufficient anti- 



