Tin-: Lrx(t PLA<;IT. OF CATTL 37 



street. New York, had a cow die August, 1S7S, of lung plague ; another 

 was put in the stable three months later, did badly, and finally (level 

 op *d lung plague in August. IS7!>. 



Another ease is that of the deer park, at IJiel, Kast Lothian, Scotland, 

 in 1851 1-V*:.'. Pasturage tor a number of cattle in this was yearly let, 

 and during the years mentioned lung plague, appeared among 1hsr 

 year after year. Yet the park was vacated by cattle, the deer and sheep 

 only being left for the five winter months, November to May. 



Other things being equal, the infection will be most lasting where it 

 has been most thoroughly dried and most closely covered up. Thus, in 

 dry, close buildings, with doors and windows habitually closed; in those 

 having rotten wood or deep cracks in the masonry, in which the virulent 

 matter may be stored away and closely covered; in those with confined 

 and unveutilated spaces under a wooden floor, and in those containing 

 rubbish, hay litter, feed, lumber, &c., the virus will be preserved much 

 longer than' in buildings that are empty, clean, open, and well-aired. 



This is only the statement of a general truth applicable to most, if 

 not all, contagions. A certain amount of air is essential to the growth of 

 a disease-poison, but an excess of air proves destructive to it when in 

 a moist condition. In preserving vaccine lymph, we receive it into ca- 

 pillary tubes, and seal them hermetically, or if it is taken on ivory points, 

 these are dried and closely wrapped in lead-foil. So in the preserva- 

 tion of lung-plague lymph Bruylants and Verriest found that after se- 

 clusion for over a month in hermetically-sealed tubes it still retained its vi- 

 tality. The germs of typhoid fever are preserved indefinitely in the close 

 sewer or cesspool, but are quickly rendered inert on exposure to the air. 

 The cholera germ is long preserved in impure soils, &c., but loses its vir- 

 ulence in five days if freely exposed to the air (Sanderson). The germ of 

 yellow fever is only preserved in the close hold or well of a ship, or in 

 the filth-laden interstices of a hot soil under a tropical sun, and loses its 

 power for mischief as soon as the air is rendered pure and wholesome. 

 The bacterium of anthrax may be cultivated in free air until it becomes 

 absolutely harmless (Greenfield, Buchner). The same is true of chicken- 

 cholera (Pasteur) and of swine-plague (Law). We may even go a step 

 farther, and say that the growth of these poisons in suitable media, and 

 in a limited amount of air out of the animal body, fits them for living 

 Avitli greater ease within the animal fluids, and thereby renders them 

 more deadly. This has been shown by Buchner in the case of anthrax, 

 by Professor Law in the case of swine-plague, and by Gravitz in the 

 case of various of the common molds. 



As this question of the vitality of lung-plague virus involves the con- 

 sideration of its conveyance through different media, it may be well to 

 advert further to some of these. 



INFECTION CARRIED IN CLOTHES. 



1st. In the winter of 1847-'4S, infected oxen were brought on the farm 

 of Pitcox, East Lothian, Scotland, and the in lection reached the neigh- 

 boring farm of Pleasauts, a mile and a half distant, in the following 

 manner : The herdsman on Pitcox being the son of the farm steward on 

 the rieasants, visited his parents on the latter place every Sunday, and 

 invariably went out to see and handle his father's cow. In a few weeks 

 this cow, which stood in a building alone, sickened, and from her the in- 

 fection spread to the other cattle on the premises. The steward's cow 

 could not have herself brought the infection to the Pleasants, as she 



