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: fectant power of lime on pens and grounds, so that more definite : 
knowledge of its efficiency on a large scale may be 6btained. 
It must be borne in mind that none of these precautions can take 
the place of the isolation of the healthy upon fresh disinfected or 
uninfected ground. No matter what may be the care taken in disin- 
fection; if one sick animal, manufacturing and carrying virus about 
within itself, so to speak, be allowed among healthy animals, the dis- 
ease will spread nevertheless. 
The experience which has been gathered at the experimental sta- 
tion during the past three years in the study of this disease has shown, 
(1). That healthy pigs can be kept free from infection, even on a farm 
where such disease 1s constantly kept up for purposes of investiga- 
tions, provided they are kept in clean pens and there is no transmis- 
sion of virus from the sick to the well through implements of various 
kinds, through the carelessness of farm hands carrying it on their 
clothes, hands, shoes, etc.; (2). That the disease may. be carried to a 
previously uninfected locality by pigs botght from unknown sources; 
(3). That the disease, supposed to be extinct, may lurk in a chronic 
orm in some animal without being recognized, and that this animal 
_ may become the source of an acute outbreak among fresh animals, 
usually in spring and fall when least expected; (4). That the safest 
method of raising swine is to breed them on the place, either known 
to be free from disease or thoroughly disinfected, and kept unoccu- 
pied for half a year after an outbreak, and not to allow any commu- 
nication with neighboring herds, nor to make any udditions unless 
the source be positively known to have been free from uisease for at 
least one year past. These rules will apply to swine plague so far as 
our knowledge of the disease goes, with exceptions mentioned in the 
article on that disease. 
FURTHER INVESTIGATIONS ON THE ETIOLOGY OF IN- 
FECTIOUS PNEUMONIA IN SWINE (SWINE PLAGUKE), 
In the report. for 1886 some preliminary investigations were re- 
corded concerning a disease in swine which differs from hog cholera, 
not only in the character of the lesions which it presents, but also as 
regards the organs attacked. The bacteria causing this disease are) 
quite different from those of hog cholera and readily distinguishable 
by a number of tests. At the time of publication the material which 
had been examined was not sufficient to warrant a detailed description, 
nor were proofs adequate for complete demonstration. In February, 
1887, an epizootic of this disease, which appeared in the District of 
Columbia, was carefully studied, and a number of additional import- 
ant observation made in connection with the peculiar lesions which 
it produces. 
‘The outbreak referred to appeared on a farm adjoining the exper- 
imental station of the Bureau in February, 1887. The farm had 
‘been free from swine diseases for several years. No clue couid be 
obtained of the manner in which the disease originated. In the 
later stages of the outbreak the investigation was complicated by the 
appearance of hog cholera in the same herd. But sufficient evidence 
had already been procured to show in a striking manner the non- 
identity of the two diseases. In this outbreak we were for the first 
time enabled to convince ourselves of the important fact that in the 
severer forms croupous and diphtheritic lesions of the large intestine 
