288 Opinions on Epidemics and Epizootics. 



been dropped by some animals on a public road, and might 

 have been picked up by some other animals ten days after- 

 wards. In other instances it has been presumed that small 

 quantities of the poison may have been carried away by the 

 boots of a grazier, by the skin of a sheep dog, or the clothes 

 of anybody who went within a few yards of a sick cow, and may 

 by some sort of contact with healthy animals have infected them. 

 Now, no presumption, however well founded, that the cattle disease 

 is highly contagious, can make it reasonable to impute to it 

 such a wonderful degree of contagious power/without multiplied 

 observation and judicious experiment, testing and verifying 

 every particular assertion. A certain number of cases seem to 

 favour the importation theory ; but even these have not been 

 critically examined. In a multitude of other cases the impor- 

 tation theory is not evidenced at all. It may be true, but it 

 has been assumed to be so, first, because it was the fashion of 

 the hour; and, secondly, because particular doctors did not 

 know how else to account for its appearance, and felt a pro- 

 fessional dislike to frankly confessing that they knew no more 

 about the matter than the cows themselves. 



Those familiar with microscopic inquiries will place no 

 limits to the smallness of the portions of matter that may 

 generate disease. A single bacterium, of the sort described by 

 M. Davaine, obtaining access to the blood of a living animal, 

 appears capable of growth and reproduction, to such an extent 

 as to occasion its death in a few days. The size of such a 

 bacterium and its weight are both infinitesimal, and other 

 germs of disease may be equally small or much smaller. But 

 if it be admitted that M. Davaine' s bacteriums cause splenic 

 disease, millions of them might fly about in the air, or attach 

 themselves to cattle, or be swallowed, or inhaled before one 

 contrived to get into the circulatory system in contact with 

 corpuscles of blood. The ultra- coutagionists have to show 

 not only the presence and diffusion of their poisons, but also 

 the manner in which such poisons can make an effective entry 

 into the system. Many poisons are only dangerous when ad- 

 ministered in a particular way. 



The Privy Council has been the death of a great number 

 of animals which might otherwise have been cured. At the 

 Sanatorium meeting, Mr. Guerrier (described as an extensive 

 cattle salesman) stated that a cargo of 108 foreign animals 

 arrived at Harwich, and one of them was suffering from the 

 malady and died. The whole of the remainder were perfectly 

 healthy, and were declared so by the inspector. These were 

 killed and sent to London, while ten others consigned to 

 another party were kept in quarantine and remained healthy. 

 These facts, as Mr. Guerrier said, clearly showed either that 



