December, ’23] burroughs & grube. lubricating oil emulsions 535 
Experiment Station, and has been successfully used by many growers in 
the State. Other growers have had trouble in getting good emulsions. 
Emulsions made according to the Government Formula have been put 
on the market by spray companies, and in some cases the growers have 
been advised to buy these rather than make their own. 
It has been stated that the oil-soap stock emulsion made according 
to the Government Formula contains 66f % oil. This is not the case. 
To make stock emulsions containing 66f % oil by volume, the following 
formula has been used here:— 
Engine Oil.2 gal. 
Potash Fishoil Soap.2 lbs. (about 1 qt.) 
Water to make total of.3 gal. (about 3 qt.) 
We have been able to make good emulsions using lb. of soap in¬ 
stead of 2 lbs. as in the above formula. These stock emulsions of oil 
and soap, containing 59-67% oil, mix freely with soft water, and are 
added to a tank of water in proper proportions. However, if mixed 
with hard water, lime-sulphur, or any mixture containing an appreciable 
number of calcium ions, spontaneous de-emulsification occurs. This is 
due to a reaction between calcium and the potassium soap, with the for¬ 
mation of a calcium soap. A calcium soap tends to stabilize emulsions 
of water in oil, rather than of oil in water. Under working conditions, 
however, de-emulsification occurs rather than a change of phase. Oil- 
soap emulsions can be “stabilized” for use with hard water and lime- 
sulphur, by the addition of glue, casein, flour, starch, etc. 3 A 
Bordeaux mixture has been widely utilzed as a stabilizer when hard water 
has to be used. 
Following the work of Pickering, 4 emulsions have been made up at the 
Missouri Agricultural Experiment Station in the cold, using Bordeaux 
mixture, and a mixture of ferrous sulphate and lime as emulsifying 
agents. Calcium caseinate, sold under the trade name of “Kayso” 
has also been used successfully as an emulsifying agent, as well as 
powdered saponin and extract of soap bark. Such emulsions have 
been made up in considerable quantity, and used in spraying over 300 
bearing trees. No statement can be made in this article as to the 
expediency of replacing lime-sulphur by oil emulsions for the dormant 
spray. However, the success attained in preparing and applying these 
emulsions, it is believed, warrants the presentation of the method of 
preparation. A comparison of the results obtained with such emulsions 
and those made according to the Government Formula is also given. 
flournal Chemical Soc. 91: 2001, 1907. 
