ground near the middle of the tent. The water and then the acid 

 were placed in this, and the cyanide, broken into small lumps was 

 placed in a loose paper bag suspended above, and held by a string 

 leading outside. The door was then shut and the string released, 

 allowing the bag to fall into the kettle. After forty minutes the tent 

 was opened and taken to another tree. Trees were fumigated in all 

 cases after 9 a. m. but in all kinds of weather. 



The trees thus treated were cherry, pear, peach and plum. None 

 showed any effect of the treatment and no living scale was found on 

 any, till late in October, when in two cases, a single young scale was 

 discovered. In both of these cases it is probable that the trees were 

 reinfested during the summer after the fumigation from badly 

 affected ones near by. 



2. Treatment with Standard Materials. 



Good's Caustic Potash Whale Oil Soap No. 3. This . soap was 

 used at the rate of two pounds to a gallon of water, heat being used 

 to dissolve it, and the solution was sprayed while warm. A Niagara 

 nozzle was used at first, but a more even distribution over the trees 

 with greater economy of material was obtained by the use of a fine 

 aperture Vermorel which was found to give no trouble by clogging 

 and which was therefore adopted for the greater portion of the work 

 with this soap. Spraying was continued in each case till the trees 

 were thoroughly covered and began to drip. 



The results obtained with this soap were disappointing. Only 

 28.12% of the trees were freed from the scale while most of those 

 which were badly infested remained so. The detailed results are 

 given below in comparison with those from the other materials. 



Bowker's Tree Soap. This is also a potash whale oil soap, manu- 

 factured by the Bowker Insecticide Co. of Boston. Like the last it 

 was used at the rate of two pounds to a gallon of water, solution 

 being hastened by heating, and was sprayed warm. It was slower in 

 dissolving than Good's soap but sprayed equally well. It appeared 

 to be more concentrated than Good's soap which perhaps explains 

 the better results obtained, 52.6% of the trees treated with it being 

 entirely freed, while none which were badly infested remained so, 

 being either greatly improved or altogether freed from scales. 



