109 



could not be mixed with the emulsion. The increase was much greater 

 where the hose was held out of the liquid, allowing the discharge to fall 

 through the air. In most cases, this increase in volume is not very 

 significant after the emulsion has cooled. The grower making his own 

 emulsion should bear this point in mind when he comes to the dilution 

 of his product. 



The data of the tables tend to prove that the amount of water 

 and soap as well as this increase in volume are factors to be considered 

 if final results are to be used in a comparative way. 



Table II 

 1. Formula: Oil 1 gallon, water % gaUon, soap 2 pounds 



2. Formula: Oil 1 gallon, water % gallon, soap 1 pound 



DE-EM ULSIFICATIOX 



Sometimes an apparently good emulsion de-emulsifies, or "breaks", 

 and the commercial orchardist generally finds that this is due to one or 

 more of the following causes : 



It is to be expected that an emulsion which contains a water phase 

 tvould be injured by freezing temp)eratures which by breaking the ex- 

 ternal or water phase frees the oil. However, it is entirely possible to 

 make a stock emulsion that will withstand continued zero temperature 

 with only negligible damage. Injury is proportional to an excess amount 

 of water in the emulsion. 



A most carefully made emulsion may, after a long period, begin 

 to de-emulsify. The air coming into contact with its surface causes 

 evaporation of the water and results in the cracking of the film around 

 the oil globules, and the droplets then coalesce. 



The presence of acids or large amounts of lime, as in lime sulfur, 

 leads to the breaking down of an emulsion in such way that re-agita- 

 tion will not restore it. 



