In addition a little Iron sulfid was found, probably coming from the 

 kettle in which the wash was prepared. The salt used did not seem 

 to enter into any of the combinations. 



Consideration of the results given above showed that the Calcium 

 hydrate, Calcium carbonate and Calcium sulfate could at once be 

 ruled out as having no insecticidal value. 



To test the action of the remaining materials separately was the 

 next step and again through the kindness of Dr. Wellington these 

 were obtained though, owing to insufficient facilities for their pro- 

 duction, it was only possible to supply them in quantities of ten gal- 

 lons each. They were applied as follows : 



The process of manufacture of these substances was such that 

 when they were obtained an excess of lime was also present in most 

 cases, but as this would have been difficult to remove at reasonable 

 expense and could hardly be a factor in the results, it was allowed to 

 remain, the amount being shown in the last column of the above 

 table. 



Each of these eight substances was applied about the end of 

 March, 1903, to from three to eight quite badly infested trees and 

 the results were studied during the following spring and summer. 



As was anticipated the Iron sulfid proved worthless as an insecti- 



