22 PROTECTION OF PLANTS, 1918-19 



the positive harm that may result from poisoned bodies of birds, are facts that 

 must be considered . But there are still other difificulties to be met with in the use 

 of poison. The sparrow manifests almost a human aversion or distrust for any 

 sort of preparation. The taste, color and smell awaken his suspicion or distrust. 

 After many attempts with the various methods prescribed in different works I 

 succeeded in poisoning scarcely fifty sparrows in ten years; although I have 

 tried most poisons, both ordinary and extraordinary. I think I have at last found 

 one that will fulfil all the required conditions: harmless to other animals, easily 

 prepared, taken readily, and so tested that I can recommend it with all confidence. 

 This poison is " Nitrate of Strychnine'". In spite of its bitterness, poisoned grains 

 are eaten as readily as those that are not so treated. Wheat grains are preferred 

 to any other kind. The grain is soaked for ten hours in water containing one per 

 cent of the Nitrate. The liquid not absorbed is drained off and used without 

 delay for another quantity of wheat, otherwise fermentation would set in and des- 

 troy the poison. The soaked grain is allowed to dry and is then ready for use. 



Usually the best time for operations is in the evening before sunset when 

 large flocks gather together on open ground near their roosting place to play and 

 eat before retiring. The grain is previously scattered about so as not to excite 

 their suspicion. The marvelous effects of this method are quickly perceived. An 

 occasional bird dies on the ground, but it happens so quietly and peacefully that 

 he does not disturb his companions. The greater part, however, find their way to 

 the trees whence they drop quietly to the ground dead. Paralysis of the vocal 

 chords prevents the usual startling cry which frequently terrorizes the yet un- 

 affected ones when other strychnine compounds are used. This latter fact is 

 of the greatest consequence. 



The time required to kill ranges from three to twenty-five minutes; but the 

 greater number die between five and fifteen minutes. An exceedingly small quant- 

 ity of poison is required for effective work, as is shown by the following figures: 



Dry wheat was used in the experiments. Thirty grains weighed one gram, 

 and one ounce of nitrate gave a solution sufficient to poison 180,000 grains, that 

 is, one grain contained one six thousandth (1-6000) of a gram, of the poison. 



Experiments performed in the Laboratory on captured live- sparrows showed 

 that three grains would kill one bird, while those poisoned in the open were found 

 to contain but three or four seeds. It is certain, of course, that only a small 

 portion of the poison eaten does the work, whence it follows that the fatal quantity 

 is less than one two-thousandth (1-2000) of a gram, while physicians usually 

 administer doses ranging from one- thousandth (1-1000) to three-thousandths 

 (3-1000) of a gram, or one-sixtieth (1-60) to one-twentieth (1-20) of a grain. 



