66 



me, has been evolved in the San Francisco oflSce as the result 

 of experience and experimentation, and has been found there 

 to be practically as efficient as phosphorus. Laboratory ex- 

 periments show that any rat that eats any quantity of this 

 poison dies within a few days. The quantity of each ingredient 

 given is large and the ordinary householder or farmer might 

 find one-tenth this amount amply sufficient for his needs. 



Wliite arsenic, finely powdered, 

 Cheese, 

 Glycerine, 

 Water, 

 Corn meal, 



Black aniline, sufficient to color to a slate gray. 

 Oil of anise. 



4 pounds. 

 4 pounds. 

 6 ounces. 

 1^ gallons. 

 10 pounds. 



J 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 

 continue 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 surrounding 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 instances may render the rat suspicious of the poison. 



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 approximately from 800 to 1,000 holes or runs. The 

 poison is placed with a small mixing spoon, somewhat similar 



