THE RAT PROBLEM. 
ratio between the attractiveness of the various baits and plain bread— 
‘the favorite food, which is represented by the figure 100 :— 
Bread (plain) .. bi .. 100 Fish (smoked) di ig (e240) 
Bread (faintly flavoured with Malt Me ae eee2) 
rhodium) .. it: .. 40 Maize x E. 20 
Bread (faintly flavoured with Dripping ere ee en 0) 
aniseed ) ¥ bee pee Ue CALVO OS aia eee AA 4 
Bread (soaked in milk) .. 60 Potatoes (mashed with milk) .. 20 
Oatmeal a ay een Ueeo Lc x85 i foal AKD) 
Tallow oe bs .. 70 Bacon bes ine ae 10 
Banana aay a .. 60 Beef extract ays vy ares, 10 
Flour and water a .. 50 Lentil meal hea a im, 10 
Oats oa ea x er Oma Hits hee (or CC) ae 7, erie! 0. 
Barley ne ee .. 50 Raw meat 7s Ai 1h 0 
Tripe ae - fo DUmee usa rs) as is, 0 
Bloatér paste .. by Pyro UNE DDL 5H cf bs 9) 
Notwithstanding the preference for certain foodstuffs used as bait, 
as indicated by the table submitted, no hard-and-fast line can be laid 
down to suit all conditions, for rats, ike many other animals, may, 
under varying circumstances, differ in their tastes. For example, quite 
recently the author tested the most favoured and one of the least 
favoured baits—as found by the London tests, and illustrated in the 
table—namely, bread and meat. The bread was plain, and the meat 
was minced. Hach was mixed with barium carbonate. They were both 
laid down at the same time and place in the evening, and on making an 
inspection the following morning it was found that the meat bait had 
all been removed, whilst the bread bait remained untouched. Again, 
where, after a while, the bait, is refused, a change should be offered. 
Poisons. 
Phosphorus, arsenic, and strychnine are often used in the pre- 
paration of rat-pastes or vermin killers, but, as they are all rapidly fatal 
in their effects on man and the domestic animals, and therefore danger- 
ous, are not recommended. There are others which, whilst being 
vapidly fatal to rats, are comparatively harmless to domestic animals. 
These: are barium carbonate and squill. 
Barium Carbonate-—Although 14 to 2 grains suffices to kill a rat, 
barium carbonate is more or less harmless to domestic animals, cats 
and chickens withstanding 10 to 15 grains, and an average-sized dog 
over 100 grains. It has also the advantage of being cheap, tasteless, 
odourless, and therefore easily made attractive by mixing with a suit- 
able bait, and has been found to be as.effective as the more dangerous 
poisons, such as phosphorus and arsenic. The bait may be prepared 
in the following manner:—Make a paste by well mixing equal parts 
of the powdered barium carbonate and tallow-fat or dripping and 
spread it over thin slices. of bread exactly as one would do with butter. 
Then, having firmly pressed the slices together to form sandwiches, 
they are cut into small squares ready for use. Of course, it may be 
mixed with any other bait found equally or more acceptable. Owing 
to the action of barium carbonate on the ling membrane of the 
stomach the rats are induced to leave their holes in search of drink. 
It is recommended, therefore, to place within reach, on the day follow- 
ing the treatment, shallow bowls containing a solution consisting of equal 
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