41 



Experiments were made with a considerable number of additional 

 repellents, to which the ants reacted so feebly or for so short a time 

 that a detail of their behavior is unnecessary. Among these were 

 pyrethrum powder, calcium carbide, capsicum, iron sulfate, chlorid of 

 lime, and tobacco, the last applied in the form of a small piece of to- 

 bacco plug which had been soaked in water. In the same class of sub- 

 stances which were more or less disagreeable to the ants, but never- 

 theless ineffective as repellents, were the following fertilizers : ground 

 limestone, rock phosphate, acid phosphate, ground sheep-manure, 

 kainit, ammonium sulfate, dried blood, bone meal, potassium sulfate, 

 sodium nitrate, and tankage — the last, a vile-smelling material from 

 the slaughter-house, so little offensive to the ants that many ef them ap- 

 proached and crawled over it freely, and even placed their larvae in 

 contact with it. Later, they dealt with this material as they did in an- 

 other case with sand — that is, they carried it out of the nest and de- 

 posited it on the glass outside or threw it into the water around their 

 cage. By 1 :15 p. m. the nest had been cleared and the ants were all 

 at home. 



Additional Field Experiments with Repellents, 1908 



After the failure of 1907 the experiments with repellents applied 

 to the seed were repeated in 1908 on a much larger scale, in the hope 

 of a more favorable season. The spring proved, however, to be similar 

 to that of the preceding year, and the results were not materially dif- 

 ferent. 



In a field of twenty-five acres near Galesburg, the use of which 

 for our purpose was secured by contract with the owners, eight plots 

 each twenty corn rows wide and eighty rods in length were planted 

 on the 23d and 25th of May with seed treated with pure kerosene, 

 kerosene emulsion, scalecide, oil of lemon, carbolic acid, and formalin, 

 two plots of twenty rows each being planted at the same time with un- 

 treated seed as checks. These materials were used in the following 

 proportions : kerosene, 1 oz. to 4 gallons of seed ; scalecide, oil of 

 lemon, carbolic acid, each in 10 per cent alcoholic solution of which 3 

 oz. were applied to a gallon of seed ; kerosene-soap emulsion contain- 

 ing 10 per cent of kerosene, also 3 oz. to the gallon ; and formalin, 6 

 oz. of a 3 per cent solution to the gallon. The original infestation of 

 this field, ascertained by Mr. G. E. Sanders, April 22, was at the rate 

 of forty-three nests to the mile of furrow. 



The weather of the spring at this place preceding the date of 



