DISEASES OF THE OX AND SHEEP. 225 



** oxygen," by which the various tissues and organs of the body 

 are kept oxygenated and active, and on the other the expulsion 

 of carbonic-acid gas, which is poisonous to animal life. Now 

 oxygen seems to be favourable to the growth and activity of 

 bacilli, while, strange to say, its more active modification, ozone, 

 seems to have a distinct retarding effect upon them. This latter 

 agent, then, may hereafter prove to be of great value in com- 

 bating germ diseases. For some time it had been thought 

 possible that this peculiar gaseous substance might have some 

 of that germicidal power of which we have now some evidence. 



Ozone is more active than oxygen. It has greater oxidising 

 powers. In pure air small quantities are found, and it also 

 exists naturally in greater amount in sea-air. It is supposed 

 to be formed, in part at least, by the electric discharges which 

 take place in storms, and there is no doubt that the reason why 

 it is not found in the air of cities is that such air contains much 

 matter which is readily oxidisable, and so the ozone is very soon 

 decomposed. Its presence in sea air is no doubt one of the 

 reasons why sea voyages often do so much good to those who 

 are weak or debilitated with disease. 



Recently Dr. Cash has confirmed the results of other investi- 

 gators in regard to these two gases. He finds that oxygen has 

 not been observed to destroy bacilli, but, on the contrary, that 

 during the process of adding oxygen a considerable increase in 

 the rate of multiplication of the bacilli was brought about. The 

 reverse is the case with regard to ozone. It had been found by 

 Binz that the chief action of ozone is a soporific one, and it has 

 this effect, even when present only in small quantities. Hence 

 we may explain that drowsiness which people feel when subjected 

 to the influence of sea air. In larger amounts ozone may bring 

 on bleeding from the lungs and bronchial catarrh. Different 

 observers agree that the bacilli which produce putrefaction are 

 destroyed by ozone, but that this agent has no action on the 

 " spores " of the bacilli. 



Dr. Cash has found that if about '00267 gram, of ozone is 

 introduced into the quantity of anthrax virus he used for inocu- 

 lating animals, the virus is destroyed ; and with his careful 

 experiments he seems to have established the facts that ozone 

 gradually weakens and ultimately destroys the virus of anthrax, 

 but that it has no destructive effect upon the " spores." Now 



16 



