HOW TO DESTROY EATS. 



15 



rat runs, about a teaspoonful at a place. If a single application of 

 the poison fails to kill or drive away all rats from the premises, it 

 should be repeated with a change of bait. 



Strychnine. — Strychnine is too rapid in action to make its use for 

 rats desirable in houses, but elsewhere it may be employed effectively. 

 Strychnia sulphate is the best form to use. The dry crystals may be 

 inserted in small pieces of raw meat, Vienna sausage, or toasted cheese, 

 and these placed in rat runs or burrows ; or oatmeal may be moistened 

 with a strychnine sirup, and small quantities laid in the same way. 



Strychnine sirup is prepared as follows: Dissolve a half ounce of 

 strychnia sulphate in a pint of boiling water; add a pint of thick 

 sugar sirup and stir thoroughly. A smaller quantity may be prepared 

 with a proportional quantity of water and sirup. In preparing the 

 bait it is necessary to moisten all the oatmeal with the sirup. Wlieat 

 and corn are excellent alternative baits. The grain should be soaked 

 overnight in the strychnine sirup. 



Arsenic. — Arsenic is probably the most popular of the rat poisons, 

 owing to its cheapness; yet our experiments jDrove that, measured 

 by the results obtained, arsenic is dearer than strychnine. Besides, 

 arsenic is extremely variable in its effect upon rats; and, if the ani- 

 mals survive a first dose it is very difficult to induce them to take 

 another. 



Powdered white arsenic (arsenious acid) may be fed to rats in 

 almost any of the baits mentioned under barium carbonate and 

 strychnine. It has been used successfully when rubbed into fresh 

 fish or spread on buttered toast. Another method is to mix twelve 

 parts by weight of corn meal and one part of arsenic with whites of 

 eggs into a stiff dough. 



An old formula for poisoning rats and mice with arsenic is the 

 following, adapted from an English source: 



Take a pound of oatmeal, a pound of coarse brown sugar, and a 

 spoonful of arsenic. Mix well together and put the composition into 

 an earthen jar. Put a tablespoonful at a place in runs frequented 

 by rats. 



Phosphorus. — For poisoning rats and mice, phosphorus is used 

 almost as commonly as arsenic, and undoubtedly it is effective when 

 given in an attractive bait. The phosphorus paste of the drug 

 stores is usually dissolved yellow phosphorus, mixed with glucose 

 or other substances. The proportion of phosphorus varies from one- 

 fourth of 1 per cent to 4 per cent. The first amount is too small 

 to be always effective and the last is dangerously inflammable. Wlien 

 homemade preparations of phosphorus are used, there is much dan- 

 ger of burning the person or of setting fire to crops or buildings. 

 In the Western States many fires have resulted from putting out 



369 



