—— 
THE RAT PROBLEM. 
trichine. Small pieces of the abdominal muscles were then—for experi- 
mental purposes—fed to a white rat, which died four days after eating 
the diseased flesh. On examination, adult trichine were found in the 
intestines. These intestines were fed to another rat, which also died 
four days later. Adult trichine were found in its large intestine. The 
carcass and intestines of this rat were then fed to three white rats. The 
carcass was freely eaten, but the intestines appeared not to have been 
touched. Seventeen days later two of them were found dead, and in 
the muscular parts of the diaphragm of one of the latter encysted 
Trichine spiralis were found. <i 
Tt would appear perfectly clear, therefore, that not only did the 
muscles of the rat secured at the piggery contain living trichine, but 
that it was highly probable that the sow became infected through the 
agency of diseased rats on the premises. 
5. Tuberculosis of the rat, sometimes termed rat-leprosy, is a chronic 
infective disease which has been found to exist in 5 per cent. of rats 
specially examined in Odessa and Berlin. The disease has also been 
described as existing in rats in this country. _ The exact relationship 
between rat tuberculosis and forms of tuberculosis amongst other ani- 
mals is uncertain, but it is believed to resemble tuberculosis of birds more 
‘closely than any other variety. 
Pseudo-tuberculosis is the term applied to another disease—highly 
infective—which exists as affecting the rat. In fact, in 1916, an outbreak 
occurred amongst trench rats in France, a considerable number becom- 
ing infected. 
As the rat possesses a high degree of immunity against the micro- 
organism causing the common form of human tuberculosis, it is con- 
ceivable that the human subject may, in a similar degree, possess natural 
immunity against the so-called rat tuberculosis. 
Ii has been definitely established, however, that human beings do 
suffer from the same form of tuberculosis as found in cattle; and by 
experience one is aware of the fact that not only healthy, but also tuber- 
culous carcasses and organs, whilst hanging in private slaughter- 
houses, are commonly overrun by rats. These rodents often cause serious 
damage to healthy carcasses; but when they overrun and eat into 
tuberctilous material, and, having got their limbs, &c., well contami- 
nated, pass on either to a healthy carcass within the same or adjoining 
slaughter-house, or to some part of the district, perhaps a dwelling, the 
possibilities of spreading disease are by no means negligible. 
Hunery Rars arn Frrocrovs. 
Many years ago, a vessel carrying cattle to this country was wrecked 
off St. Mary’s Island, on the north-east codst. Some weeks later a 
number of workmen had occasion to visit the vessel. Not long had they 
been on board when large numbers of long lean rats made their appear- 
ance and attacked the men. The latter took refuge up the rigging, and 
finally had literally to fight their way ovérboard and make their escape 
by rowing from the ship “for all they were worth.” 
The late Mr. R. Stephenson, M.P., related a peculiar affair. In the 
Walker colliery, in which many horses were employed, the rats had 
accumulated in great multitudes. It was customary, at holiday times, 
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