i6 



ments which does not as yet seem to have been consistently made 

 would be to prepare washes using fifteen, twenty, twenty-five and 

 thirty pounds of lime to fifteen pounds of sulfur, boiling in each 

 case for the same length of time ; a similar series wherein the 

 amount of sulfur should be the variable factor; a third series 

 in which for each combination of lime and sulfur the time of 

 boiling should vary and a fourth in which the amount of water used 

 during the boiling should be the varying factor, as it is possible that 

 this has something to do with what might be termed the " opportun- 

 ity" the materials would have to combine in different ways. It has 

 been noticeable, in comparing the results obtained in different 

 parts of the country, that in general the best results have been 

 reported where quite large amounts of lime and sulfur have been 

 taken and the boiling has been for at least three-quarters of an hour 

 in a considerable amount of water. 



The cost of the materials for the lime-sulfur wash is less than for 

 any of the other sprays thus far considered, and the drawback it has 

 is the cost of apparatus for boiling and the time required. 



Self-boiled Washes have been quite widely tested to avoid the 

 difficulty just mentioned, caustic soda, sal soda or sodium sulfid 

 being added to continue the boiling begun by the slaking of the lime 

 and thus produce the chemical combinations desired. The cost of a 

 boiling apparatus is saved in this way but that of the chemical 

 added in part offsets this and the results have been very variable, 

 due probably to a more or less partial failure to obtain sufficient heat 

 for a sufficient length of time. While excellent results have occa- 

 sionally been reached the average of the reports indicates that this 

 method fails to equal the results from the boiled wash. 



Blue Vitriol added to the boiled wash has been tested with some 

 apparent success, but Thatcher finds that this combines with the 

 higher sulfids rendering them insoluble and the value of this wash 

 on the theory of its action given above would then depend entirely upon 

 the thiosulfate present at the time of application. 



Miscellaneous inaterials mainly in the form of "Proprietary Insecti- 

 cides " have been placed upon the market in great numbers and 

 many of them have proved to be of no value whatever, so far as 

 tests show. The more important of these and the average results 

 given by their use follow. 



