410 THE GYPSY MOTH. 



Creosote Oil. March 14. A small amount of creosote 

 oil was dropped upon five egg-clusters, and, although it did 

 not appear to injure the eggs, none of them hatched. March 

 31. A mixture of creosote oil and pine tar, fifty per cent, 

 of each, was dropped upon some egg-clusters. It pene- 

 trated them at once, and, later, shrivelled the eggs so that 

 none hatched. March 3 1 . Another lot of egg-clusters was 

 treated in the same manner, and the eggs destroyed. Two 

 experiments with a mixture of creosote oil, fifty per cent., 

 and turpentine, fifty per cent., gave results like those of the 

 preceding experiments. April 7. About eight thousand 

 eggs were saturated with a solution of pine creosote oil, 

 forty-five per cent., turpentine, forty-five per cent., and 

 coal tar, ten per cent. It penetrated the egg-clusters read- 

 ily, and attacked the eggs so that none hatched. 



Goal Tar. March 5. A mixture of coal tar, thirty per 

 cent. , phenol, forty per cent. , and turpentine, thirty per cent. , 

 was dropped upon ten egg-clusters. It quickly penetrated 

 the eggs, turning them black and softening the shell so that 

 none hatched. Several other experiments with similar tar 

 mixtures gave equally as satisfactory results. 



Eagle Mills Powder. March 11. A mixture of Eagle 

 Mills Powder, fifty per cent., and turpentine, fifty per cent., 

 was dropped upon ten egg-clusters, but the mixture was too 

 thick to penetrate. March 11. A solution of Eagle Mills 

 Powder, ten per cent., water, sixty per cent., and alcohol, 

 thirty per cent., was dropped on some egg-clusters, and 

 quickly penetrated to the bottom. This did not injure the 

 eggs, for, by April 12, nearly all had hatched. 



Hydrocyanic Acid Gas. January 11. One egg-cluster 

 was submitted to the action of pure concentrated hydro- 

 cyanic gas, in the following apparatus : A Florence flask, 

 containing one-half an ounce of potassium cyanide and about 

 twenty cubic centimeters of water, was connected with a 

 wide-mouthed bottle by a tube bent twice at right angles. 

 The bottle also contained an escape tube. An unbroken 

 egg-cluster was placed in the bottle, then sulphuric acid was 

 added to the potassium cyanide in the flask. The hydro- 

 cyanic acid gas passed over into the bottle, driving the air 



