SCIENCE AND INDUSTRY. 
Amongst other traps successfully employed are the ordinary cage 
trap with bait hook, and with a platform connected by a spring with 
the door; the steel gin trap, a type generally popular with the game- 
keeper; and break-back traps. 
Huntine. 
Hunting with dogs and ferrets is a method generally employed in 
country districts, about farms, hedge-banks, and other places. 
Virus. 
It would appear that, in many cases, the use of virus has proved 
very satisfactory, in some fairly satisfactory, and in others distinctly 
disappointing. It is probable that, in some eases, owing to improper 
exposure, the virus loses its virulence. i 
Further, it is possible that, in some Gases, hasty conclusions haye 
been arrived at before the disease, if conveyed, has had time to incubate 
and declare itself. Again, as in other diseases, it seems probable that 
many rats possess a certain degree of natural immunity, and are not 
affected, whilst many that are affected receive the disease in a mild 
form, gradually recover, and thus acquire a certain degree of immunity 
or protection against a second attack. Finally, the warning as to the 
use of poisoned baits applies equally to the employment of rat viruses, 
that is to say, it is important to avoid contamination by the virus of 
any material likely to be used for food. 
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