cexx Proceedings of the Asiatic Society of Bengal. [N.S., XV. 
bodies ser a view of panera se elias economic loss. Rat 
destruction as an anti-plague measure s, howe arried out on a con- 
si jakte scale and it is in this direction that most penagseie has been made 
in recent hese 
A 
plague naka of Teeiling the ahelies and ye supply of rats, and by 
fontring their agi al enemies, and by means of traps and, possibly also, 
d bai an ideal always to be aimed at. But these Pipa 
offer little prospect of bringing about, at an early date, a permanent and 
universa in their numbers sufficient to oe ita ably 
the iene oe ail It may, thy not be impossible to eradicate 
plague from a large part, if ps t from the whole of India, by means of a 
temporary reduction in the rat population Pe ovided that this reduction is 
concentrated at the right time in the right place, namely before or during 
the off-plague season in the Sos SRE ea w places which threaten to 
earry infection over that period. Research haa. hown th any rate 
od. 
in some parts of India, these places can be detected with a fai r degree of 
accuracy and without any great difficulty. If these measures should 
a r olved 
Investigations have ently been conducted with a view of i v 
ing the methods of rat destruction. Thou incomplete, hey have 
path y aque that there is a great variation in the efficiency of p: 
tra B or alterations and adjustments in their structure and b 
cease cleat of the substance with which ie Fi are baited the 
number of rats caught in them can be gr gal incre 
bee 
o the present time attention has aig HI aaubhag ena to 
effecting improvements in poisone i y um carbonate has now 
n . ae. best pss ; three grains of this is sufficient to kill 
a full-gro As an ex in 
Gaus 12 gr peut resh. shly pr cae ed from the flour fi is in common use 
by the people of the locality has proved to be the bes 
ome of the more important results hitherto obtained in a large 
series of experiments are summarised in the following ta bles 
y Oe - I ginseng Bie made with the same food basis Sabre with ee 
mixed together per laid in groups in various house 
pa the ay te eh results: 
Baits used. No. set. No. taken. whe using 
o af a 
Barium carbonate baits a 282 171 | 60°6 
Phosphorus baits esi 282 61 21°6 
Control baits (no poison) oe 282 155 | 55°0 
(6) In Laboratory.—The number of rats ts used in each experiment was 
150, i.e. 15 batches of 10 rats each. The — or foodstuffs in measured 
quantity were offered simultaneously to batch of rats in a specially 
designed cage for a constant period varying ear } to $ an hour as found 
convenient, The amount consumed in each observation was then 
as follows :— 
