THE HAT PROBLEM 181 



other places it may be used very effectively, and still, on 

 account of its intensely bitter taste, it seldom catches the sly 

 old ones. Strychnized grain used in poisoning sparrows is 

 equally effective for rats and mice (|- oz. strychnia sul- 

 phate dissolved in 1 pint of boiling water, thoroughly stirred 

 into 2 quarts of cracked corn or wheat, dried and labeled 

 jind stored safely for use). The writer has been told of 

 clearing a barnyard and large stable by first feeding the 

 rats with raw, unbroken eggs, then substituting eggs heavily 

 charged with strychnine, the crystals of the poison being 

 pushed through small holes in the shells. The ground near 

 ~hese eggs was described as " strewn with dead rats." 



Phosphorus pastes commonly sold as rat and mouse poisons 

 cannot be recommended, as they are too likely to cause fires. 

 The other ingredient, glucose, is likely to be leached or weath- 

 ered away, leaving the phosphorus strong enough to ignite 

 spontaneously, and lumps of the material may be carried by 

 rats from perfectly safe places in a cemented cellar up 

 into the nests anywhere in the building. Even fields of grain 

 have been fired in this way. 



Fumigation with poisonous gases is perhaps the most effec- 

 tive method of dealing with vermin that burrow. It is such 

 sport to absolutely exterminate rats from fields, dumps, poultry 

 yards, and cellars that the game is worth the expense. 



Carbon bisulphide is the agent most commonly used. Moisten 

 a tuft of cotton or a rag the size of an egg with about a table- 

 spoonful of the bisulphide, push it down the hole, and tamp 

 bightly with earth. If the hole is dug out, and remains inhabited, 

 which can be ascertained by filling the mouth with earth a 

 few times, repeat, using a double dose. Carbon bisulphide is 

 poisonous to breathe and is not only highly inflammable but 

 very explosive ; therefore keep all lights away while using. 



What we have called the " focal " method of dealing with 

 civic pests consists in discovering something which attracts 



