63 
was the first to suggest and announce this remedy, I was the first to 
prove and announce positively that it is both safe and effective. So far 
as I know I was also the first to determine the best proportion—1 pound 
to 200 gallons of water—and to show that it is safe tc pasture in an or- 
chard at once after the poison is applied if the application is properly 
made. 
Mr. Osborn read the following paper: 
AN EXPERIMENT WITH KEROSENE EMULSIONS. 
By HERBERT OSBORN, Ames, Iowa. 
The most satisfactory method of preparing the valuable kerosene 
emulsion is desired by all and a comparative test made this season may 
be of interest. 
The first was a preparation in which the formula advocated by Pro- 
fessor Cook was carefully followed, using the hard soap and not the 
soft-soap formula, the materials while still hot being thoroughly mixed 
with an egg beater. 
The result was that we had what appeared to be an excellent emul- 
sion, but in a glass jar we could soon see a separation taking place, the 
white emulsified pari rising to the top and the water or soapsuds 
gradually increasing at the bottom. This continued until there was ~ 
about two-thirds or a little more of soapsuds and one-third or less of 
emulsion above it. 
While this at first could be readily mixed again a day later, the soap- | 
suds in the bottom had hardened into a jelly that when mixed with 
additional water would but incompletely dissolve and the clots included 
caused great inconvenience by clogging the nozzle. ‘ | 
The other preparation made according to the usual formula for soap 
emulsion (the Riley-Hubbard formula) emulsified and remained fixed 
with but a very few drops of soapsuds gathering at the bottom, even 
after days of standing, showing that the proportions were such that 
the soap water and kerosene balanced each other. This thickened to a 
buttery consistence, but dissolved perfectly in water, and only a trace 
of oil arose to the surface when thus mixed. 
A microscopical examination of the substance prepared by Professor 
Cook’s formula showed the buttery mass above to be apparently a good 
emulsion and the jelly-like mass below to contain scarcely any traces of 
oil globules. A similar examination of the second preparation showed 
in different samples as usual a uniform emulsion. 
I conclude that in the first case I formed an emulsion, that is the oil 
_ was broken into minute globules and these coated with a film of soap- 
suds so that they did not coalesce, but that there was such an excess of 
soapsuds that the emulsion separated therefrom and rose to the top. 
It is evident, I think, at sight that the preferable preparation is the 
