300 THE DISEASES AND DISORDERS OF THE OX. 



has the further advantage of lesseniog the period during which 

 alarm is felt as to the results of having been bitten. 



If hydrophobia were about to make its appearance, it would 

 be hastened by the inoculation of a virus stronger than that 

 introduced by the bite. When the middle of August had come, 

 M. Pasteur felt confident that the boy was out of danger, and 

 when three months and three weeks had elapsed after the accident, 

 his health was very good. Hence M. Pasteur has proved that if 

 rabical marrow is placed in contact with dry air, its intensity is 

 gradually diminished, and finally extinguished. Consequently 

 it would prima facie seem that in the first place virus with no 

 appreciable activity should be used, next virus with a very little 

 strength, and finally the strongest virus. But on more careful 

 consideration this view seems to be a doubtful one. The 

 lessening of the virulence may possibly be due to the diminished 

 quantity of the rabical virus, and not to its diminished 

 virulence. It is a matter of difficulty to decide this question. 



Now it is known that many microbes seem to give birth in 

 their growth to matter which has the property of hindering their 

 own development. The microbe found in some fevers seems to 

 be combated by a substance of its own creation, and M. Roulin 

 has shown that the fungus Aspergillus niger develops a sub- 

 stance which checks its growth. It is possible, then, that the 

 rabical virus is formed of two distinct substances, one living and 

 capable of developing in the nervous system, and another not 

 living, but having the faculty of counteracting or even arresting 

 the growth and development of the first. It is impossible to 

 over-estimate the far-reaching importance of this clue, and pro- 

 bably it will be found in the future to lead to discoveries 

 the brilliancy of which as yet we can by no means fully 

 realise. 



Before concluding our short review of rabies, we may 

 repeat that all oxen, sheep, dogs, or any other lower animals 

 affected with rabies, must be slaughtered, and their carcases 

 buried with antiseptic precautions. If there is some doubt 

 whether the disease be rabies or not, it is best to have the 

 animal killed, in order to be on the safe side. The untold havoc 

 which a rabid dog may bring about, even in one day's peram- 

 bulations, is frightful to contemplate, and it is most wise that 

 the muzzling orders should be strictly enforced in all towns and 



