174 THE ENGLISH SPARROW IN AMERICA. 



SECTION FOURTH 



DESTRUCTION OF THE SPARROW BY POISONS. 



By Dr. A. K. Fisher, Assistant Ornithologist. 



From time to time numerous letters of inquiry have been received by 

 the Department asking for detailed instructions in regard to the de- 

 struction of English Sparrows by poisons. So few reliable facts could 

 be procured on the subject that it was found necessary to conduct a se- 

 ries of experiments in order to obtain the desired information. It was 

 important to determine ilot only what poison is most efficient and best 

 adapted for the purpose, but also the most economical poison, the quan- 

 tity necessary for use, and the simplest practicable method of prepara- 

 tion. With these objects in view a large number of healthy English 

 Sparrows were secured and confined in large cages. They were given 

 an abundance of food and water during the time covered by the experi- 

 ments, so that they might not be forced from hunger to partake of the 

 poisoned grain. 



THE POISONS USED IN EXPERIMENTS AND THE FORMULA FOR THEIR 



PREPARATION. 



The following poisons were used in the experiments : Strjchnine; ar- 

 senic ; corrosive sublimate. 



Of strychnine, two preparations were used : Crystals of strychnine; 

 tincture of mix vomica. 



Of arsenic the following preparations were used : Arseuious oxide 

 (white arsenic); arsenite of copper (Paris green); arsenite of calcium 

 (London purple); arseniate of soda; liq. potassii arsenitis (Fowler's 

 solution). 



The results of these experiments have led to the recommeudation of 

 the following formulae as simple, efficacious, and inexpensive: 



Arsenic— Oue part by weight of white arsenic to fifteen parts of corn-meal or grain. 

 Paris green and London purple would be just as valuable as white arsenic except 

 for tbeir bright color, which arouses the Sparrow's suspicious. 



Directions : If corn-meal is used, the arsenic should be stirred in dry, and the mixt- 

 ure afterward moistened. It should be- fed moist. If whole grain is used, it should 

 be moistened before stirring in the arsenic. It will be found advantageous to add a 

 little gum arabic to the water used to moisten the grain, as it causes the poison to 

 adhere more firmly to the kernels. It should be dried before using.. Wheat is prefer- 

 able to all other grain, because the Sparrows feed upon it more eagerly. 



Strychnine.— Dissolve 2 grams of strychnine in a liter of hot water. Ordinarily, 

 (strychnine is put up in bottles containing £ ounce. Half of the contents of one of 

 these bottles, dissolved in a quart of hot water, gives a solution of the desired strength. 



Directions: To insure the best results it is necessary to soak the grain in the poison 

 solution at least forty-eight hours. It should then be dried. Graiu prepared in this 

 way may be kept in jars, to be used as required. 



