POISONING AND TRAPPING 289 



stroying rodent pests," and as insecticides and 

 other poisons for the entire country cost many 

 millions of dollars annually, the saving of waste 

 in this item of agricultural expense is seen to 

 be important. 



Probably the buyer of proprietary poisons 

 has the greatest cause for complaint. Often 

 one or two cents' worth of material is retailed 

 at from 25 cents to a dollar. The difference be- 

 tween the cost of the material and the selling 

 price represents the manufacturer's profit and 

 the retailer's profit. Such large returns enable 

 proprietors to spend much money in advertis- 

 ing or otherwise exploiting their wares, which, 

 if not worthless, are never so good as an intel- 

 ligent man may compound for himself at a 

 small fraction of their price. It is to enable 

 the readers of this book to do so that the in- 

 structions which follow are here given. They 

 are formulas which have been dictated by scien- 

 tific knowledge and approved by experience; 

 and the methods of application recommended 

 are those which have been found to involve the 

 least possible danger to man, to domestic stock, 

 and to valuable wild birds and mammals. It 



