224 BOARD OF AGRICULTURE. [Pub. Doc. 



and now and then a poisoned rat may die in the house in spite 

 of all precautions, but if the directions hereinafter described 

 are followed, this mishap is not likely to happen often. 



There is nothing new known in rat poisons. Those most 

 commonly used are arsenic, phosphorus and strychnine. Com- 

 mon arsenical poisons are white arsenic or arsenious acid, and 

 two other forms of arsenic, Paris green and arsenate of lead 

 (London purple is rarely utilized). Squill, mix vomica, cyanide 

 of potassium, corrosive sublimate (bichloride of mercury), 

 hellebore, henbane, hemlock seeds and some other poisons have 

 been used with varying results. Squill {Scylla maritima) is 

 toxic or poisonous for rats, and in the quantities prepared for 

 them is not fatal to larger animals. As arsenic, strychnine or 

 phosphorus form the basis of the greater part of all the success- 

 ful rat poisons used in this country, and as they are perhaps 

 as effective as any in use, the various means of utilizing them 

 will be considered here. The reader may inquire, if these 

 poisons are effective, why recommend more than one? Un- 

 fortunately, with poisons, as with traps, we depend on the co- 

 operation of the rat, which we cannot always secure. If the 

 rats have tasted elsewhere the combination that we offer them 

 they may refuse to touch it, and it may be necessary to try 

 some other formula; or they may have already taken small 

 doses of arsenic, for example, and may be somewhat resistant 

 to its effects. Hence a number of different poisons and dif- 

 ferent preparations of each are given. 



The chief difficulty in the effective use of arsenic and strych- 

 nine is to disguise them so as to get them into the rat in 

 sufficient but not excessive quantity. Strychnine has a bitter 

 taste; arsenic is more or less gritty in the mouth; phosphorus 

 is easily detected, yet rats seem to like it, and for this reason it 

 is one of the most effective rat poisons, if properly prepared 

 and used. No one should u^e any of the recipes or formulce 

 given here without first reading all that is written in this bidletin 

 about poisons and their uses. 



Arsenic. — Arsenic (arsenious acid) being chemically un- 

 changeable retains its toxic properties indefinitely under all 

 conditions, and may be easily disguised, therefore it should be 



