OBSERVATIONS ON THE LUNG PLAGUE OF CATTLE. 713 
The stables had meanwhile been thoroughly disinfected, and the 
greatest precautions were taken to shut up all channels of in¬ 
fection, and not one of these steers contracted lung plague. 
Yet the popular prejudice against swill is not devoid of founda¬ 
tion. To the distillery stables gravitate cattle from all regions 
for fattening. If lung plague exists in the district, such stables 
therefore become early infected, just as dealers’ stables do in the 
same localities. In the swill stables the warmth and close 
reeking atmosphere greatly favour the preservation of the virus 
and its conveyance from beast to beast. But it is further to be 
noted that in these stables the stock is arranged in rows, and a 
whole row of fifteen to twenty cattle is fed from the same 
trough. The trough is gently inclined from end to end, and 
the liquid swill runs into the trough from a pipe at the one end 
and slowly passes in front of each animal in succession to the 
other. If a sick beast stands in such a row the infected breath 
blows on the passing liquid, and the virulent expectorations drop 
into the feed to be carried on to be inhaled and swallowed by all 
susceptible animals farther on in the same row. It may be that 
the virus introduced into the stomach is harmless, as implied in 
a solitary experiment at the Alfort Veterinary College, yet as 
cattle breathe on their food, there cannot be a doubt that the 
virulent matter in the swill as in other fodder makes its way to 
the lungs in the breath, and that infection from this food takes 
place in the ordinary way. 
The Lung Plague peculiar to Bovine Animals. —While 
cattle of all kinds are susceptible to the virus of lung plague, 
this susceptibility is limited to the bovine family. In the 
zoological gardens of Europe buffaloes and yaks, &c., have 
fallen victims to it, but in no instance has it been shown to 
extend to the smaller ruminants (sheep, goats, deer). This is 
the more remarkable that the small ruminants have often 
mingled freely in pastures, and even in close buildings with 
cattle suffering from this complaint. In this respect, there¬ 
fore, the lung plague differs essentially from the other great 
scourges of cattle—rinderpest, aphthous fever, anthrax, tuber¬ 
culosis, and milk-sickness. 
Incubation, its Limits. —The occasionally prolonged period 
of incubation, during which the virus remains dormant in the 
system of an infected animal, is one of the most redoubtable 
features of this disease, and demands from the official sanitarian 
a series of precautions which are not required in other cattle 
plagues. While incubation may be as short as six days in hot 
weather, it may none the less be extended to sixty days (Dela- 
fond, Verheyen), sixty-seven days (French Commission), ninety 
days (Reynal), or 104 (Roll, Gamgee). 
