SEVENTEENTH ANNUAL MEETING. 89 



soluble oil. As a rule a slight increase in the proportion of 

 water will produce the desired effect. The proportion of crude 

 petroleum herewith recommended, it will be noticed, is con- 

 siderably greater than that recommended in Bulletin No. 49 

 of the Storrs Experiment Station. The quantity which may 

 be used depends greatly upon the quality of the crude i)etro- 

 leum and to some extent upon the efficiency of the emulsifier. 

 W ith a well-made emulsifier and a good quality of crude pe- 

 troleum as many as 45 parts of the latter have been used with 

 excellent results. The emulsifier and the rosin oil being the 

 more expensive items in the production of a soluble oil, it is 

 important that they be made to carry as much crude petroleum 

 as possible. In other words, the cost per gallon of soluble oil 

 is reduced by increasing the proportion of crude petroleum. 

 Before making up large quantities of "soluble oil" it seems 

 adinsahlc, therefore, to ascertain by experiment hozv much 

 crude petroleum may be used. In some instances it may be 

 found that the proportion of 23 parts is too high. Of a great 

 many samples tested, however, only one failed to permit of 

 its use in the proportion. If, after carefully following the 

 directions and after increasing the proportion of water, a suit- 

 able "soluble oil*' is not produced, it may be accomplished by 

 reducing the proportion of crude petroleum. It would appear 

 from the foregoing that the successful preparation of a "sol- 

 uble oil" is a very difficult and uncertain undertaking. Such 

 is not the case, for under ordinary circumstances, many of 

 these instructions, explanations and precautions are unneces- 

 sary. 



Materials. 

 A few reports have been received from fruit growers to 

 the effect that after carefully following the directions given in 

 Bulletin Xo. 49, they have been unsuccessful in making up a 

 soluble oil. In every case the failure has been traced to the 

 door of the local druggist, who either deliberately or uninten- 

 tionally misrepresented the materials used. It is extremely 

 important that the materials used in the emulsifier are of the 

 proper grade. The only safe course to pursue is to secure 



