^i^v^o . 51 



=^^ 



Rats seek water when poisoned and are likely to pollute any receptacle 

 in which it is contained by dying within it or vomiting into it. Some 

 breeders of birds make a practice of placing a vessel containing poisoned 

 water near the poisoned bait so that the rat may get a double dose when 

 he attempts to slake his thirst. 



GOVERNMENT RAT FORMULA.— The poison formula used by 

 government officials at San Francisco in combatting rats is detailed by 

 Dr. Forbush as follows: 



White arsenic, finely powdered 4 pounds 



Cheese 4 pounds 



Glycerine 6 ounces 



Water 13^2 gallons 



Corn meal 10 pounds 



Black analine, sufficient to color to a slate gray. 



Oil of anise 3^ ounce 



"Melt the cheese with the glycerine and one-half gallon of the 

 water, then add the corn meal and the balance of water, and con- 

 tinue to heat until the corn meal is thoroughly cooked. Then stir 

 in the arsenic and black aniline, and lastly add the oil of anise. It 

 may require more or less water for the above formula, according 

 to the amount of starch in the corn meal, but the quantities as 

 given above are for average quality of corn meal. 



"It is essential in the preparation of this poison that the 

 arsenic be powdered as finely as possible, in order that there shall 

 be no grit in the paste when completed. The black aniline is added 

 until the color of the paste is a slate gray, the idea being to have 

 the color of the poison approximately the same as that of the sur- 

 rounding ground. In this manner it does not attract the attention 

 of children, dogs, chickens or other animals. 



" In the preparation of the paste none of the ingredients should 

 be handled by the bare hands, as there is reason to believe that the 

 odor of the human being attaches to the poison, and in some in- 

 stances may render the rat suspicious of it. 



" The paste when finished is placed in ordinary tin fruit cans, each 

 can containing four pounds of paste. Each man places one can per 

 day, and each can of four pounds should be sufficient to poison approx- 

 imately from 800 to 1,000 holes or runs. The poison is placed with a 

 small mixing spoon, somewhat similar to a cheese scoop, and a piece 

 approximately the size of a hazelnut is placed in each hole or rat-run, 

 in such manner as to be thoroughly concealed from the observation 

 of any person or animal except the rat which uses the hole or ruri. 



