63 



as about a tablespoonful of arsenic to half a pint of melted 

 lard, well mixed when hot and then cooled. Such a mixture 

 may be used to advantage in the coldest weather, as it hardens 

 but does not freeze. This contains only about 8§ per cent of 

 arsenic. A heaping thimbleful should be sufficient for one rat. 



Arsenic, lard and corn meal: Dr. Rucker has sent me from 

 Xew Orleans the following formula: arsenic 20 per cent, lard 

 34 per cent, corn meal 46 per cent. (Note the per cent of 

 arsenic.) Half a thimbleful of this mixture placed in a rat 

 hole ought to kill any rat that eats it. Cheese, mutton fat, 

 and other bases may be used to deceive rats. Arsenic should 

 be finely powdered when used as a rat poison, and when sugar 

 is used with it brown sugar, which is moist, probably is best, 

 but powdered sugar, which resembles arsenic somewhat in 

 appearance, may disguise it better than the ordinary granulated 

 article. 



Waterton, the English naturalist, whose house was overrun 

 with rats in his absence, gives the following as an effective 

 mixture : — 



Arsenic and oatmeal: a washbasin full of best oatmeal, two 

 pounds of coarse brown sugar and a good dessertspoonful of 

 arsenic, well mixed. A tablespoonful should be pushed well 

 into every rat hole.^ Assuming that a washbasin holds three 

 quarts, the quantity of arsenic as compared with the other 

 ingredients would be about ^ of 1 per cent. 



As washbasins now made hold from two to six quarts, some 

 more exact recipe is needed, and this is given by Professor 

 Lantz, as follows: take a pound of oatmeal (not rolled oats), a 

 pound of coarse brown sugar and a spoonful of arsenic; mix 

 well together and put the composition into an earthern jar. 

 Place a tablespoonful in each run frequented by rats. 



This formula has been given a wide circulation. It has two 

 great advantages: (1) it is a nearly dry mixture and cannot 

 freeze, and therefore can be used in the dead of winter, when 

 rats need food most and are easily poisoned; (2) it does not 

 stick together, and therefore cannot be carried about by rats, 

 like bread and butter or arsenic pills, and perhaps left where 

 domestic animals can get it, but I have never known this 



' Waterton, Charles, Essays on Natural History, 1871, p. 240. 



