82 THli CONNECTICUT POMOLOGICAL SOCIETY. 



present paper. When water is added to a so-called "soluble 

 oil" it immediately breaks up into very fine particles or glob- 

 ules. In other words, an emulsion is formed. The oil has 

 not been changed in any way, for under certain conditions 

 its globules may be reunited and present the same appear- 

 ance as before. In general appearance the emulsion resem- 

 bles milk. As seen under the microscope also, the emulsion 

 closely resembles milk. The only apparent difference is that 

 the globules are more uniform and somewhat smaller. These 

 emulsions are quite stable, often remaining in perfect con- 

 dition for several months. On standing a few days, a thick, 

 creamy layer, which may be readily redistributed throughout 

 the mixture, will form on top. Just why these oil globules 

 remain distinct and suspended in water so long is not well 

 understood. 



Oil vs. Lime-Sulphur. 



In comparing the value of two or more insecticides, a 

 subject into which so many factors enter, we are very likely to 

 overlook many important considerations. In order, then, that 

 we do not too hastily form a conclusion with regard to the 

 relative merits of oil and the lime-sulphur wash, for the treat- 

 ment of the San Jose scale, it may be well to ' consider the 

 subject under the following heads : 



EMciency. The first and all-important quality in a 

 scale remedy is that it should kill the scale. Experience tells 

 us that the lime-sulphur wash, when properly made, and that 

 an oil preparation of the proper strength, will kill every scale 

 with which they come in contact. Assuming this to be true 

 we have simply to determine which~ one of these sprays is 

 likely to come in contact with the greatest number of scales.. 

 The lime-sulphur wash usually contains an excess of lime,^ 

 and, owing to the general consistency of the material, demands 

 the use of a moderately coarse nozzle. The material neces- 

 sarily must be applied in coarse particles rather than in the 

 form of a fine mist or fog, and fails to penetrate beneath the 

 outer layer of insects, under bud scales, or among plant hairs.' 

 The twigs of many fruit trees, more especially those of apple 



