No. 4.] RATS AND RAT RIDDANCE. 233 



not seen at all. Mrs. Marshall asserts that rats take cheese 

 in preference to grain. Probably the aroma of strong, fragrant 

 cheese disguises the taste of the strychnia until the deed is done. 



PhospJiorus. — This is perhaps the most widely used poison 

 for rats and mice, and is every effective if properly prepared 

 and used. In an experiment with phosphorus conducted by the 

 Massachusetts State Board of Agriculture the rats disappeared. 

 Many recipes for making phosphorus compounds have been 

 published, but I cannot recommend any of them for general 

 use, as many fires have resulted from the use of homemade 

 preparations. 



Professor Lantz says that the phosphorus paste of the drug 

 stores is composed commonly of dissolved yellow phosphorus 

 mixed with glucose or other substances, and that the pro- 

 portion of phosphorus varies from ^ per cent, which is too 

 small to be always effective, to 4 per cent, which is dangerously 

 inflammable. He has proved by experiment that a commercial 

 phosphorus paste when exposed to sun and rain became so 

 changed that it set fire to paper. 



The paste is for sale either as such or under some other name 

 as a rat poison at many drug stores and some grocery stores, 

 and those who wish to experiment with it can obtain it without 

 diflSculty. Its odor, unless disguised, usually is something like 

 that of matches, and it shines in the dark, which, no doubt, 

 attracts the rats to it at night. It may be spread like butter 

 on bread or cake, and when swallowed by the rats creates an 

 intense inward burning and thirst, so that if no water is avail- 

 able upon the premises they will leave at once, if possible, in 

 search of it. 



Mr. F. L. Hitchings of the State Fish Hatchery at Sandwich, 

 Massachusetts, makes an effective phosphorus poison by placing 

 six bunches of Portland Star matches in about a pint of water 

 that the heads may soak over night. In the morning he stirs 

 into the resulting solution granulated Indian meal, enough to 

 take up the water. 



Barium Carbonate. — The Biological Survey, United States 

 Department of Agriculture, recommends barium carbonate as 

 one of the cheapest and most effective poisons known for rats 

 and mice. Prof. David E. Lantz says that it has the advantage 



