366 THE MONTHLY BULLETIN. 



One teaspoonful of the poisoned grain is sufficient for each hurrow. It should be 

 placed on dry, hard surface outside the burrow. 



Follow directions carefully. 



If the best results are to be obtained, alkaloid strychnine must be used for the 

 following reasons: Alkaloid strychnine is soluble in about 05,000 parts of water, 

 and the sulphate in about 40 parts, therefore the sulphate is more bitter than the 

 alkaloid and consequently distasteful. 



The reason soda is used in Formula No. 2S is, that it makes the alkaloid insoluble 

 and when insoluble it is tasteless, and therefore more readily eaten by rodents. 



The chemical formulas of the two forms of strychnine differ. Sulphate contains 

 sulphuric acid and water, which are not found in the alkaloid, and which go to 

 make up one-fourth of its weight, or in other words, one ounce of alkaloid strychnine 

 contains 100 per cent poison, while one ounce of sulphate contains only 75 per cent. 

 Therefore, in poisoning 42 quarts of oats, for example, it would require three ounces 

 of alkaloid strychnine, but if sulphate is used four ounces would be required. 

 Sulphate is not recommended, for the difference in the solubility of the two forms 

 of strychnine practically prohibits its use. 



Editor's Note. — Since the above article was received for publication, County Horti- 

 cultural Commissioner S. V. Cbristiersou of San Luis Obispo County has tested a 

 sample of poison which was sent to this office by Mr. Burnett, who requested us to 

 have it tried on Citelhts beecheyi under California conditions. We quote from a 

 letter written to State Horticultural Commissioner Hecke on August 23, in which 

 Mr. Christierson writes of his test of the sample as follows: 



"I have tried it out, the whole bag, in probably one of the worst squirrel-infested 

 places in the district, and to the best of my knowledge, the approximate two gallons 

 sent, produced the net result of killing four squirrels. Examinations were made 

 three days in succession, one squirrel was picked up the day after the poisoned oats 

 were put out, two the second day, and one the I bird day. 



"Of course, I do not know the formula used, but one reason it did not work was 

 because it was not eaten very readily, as the squirrels here are used i« barley and 

 wheat, not to oats." 



