129 
producing a fungicide and also an insecticide for both sucking and 
biting insects. 
(5) Resin wash. — Within the past few years the resin washes have 
come into quite general use. especially on the Pacific coast. The inter- 
est in them has been largely due to the efforts of the CT. 8. Entomo- 
logical Division, whose agents M ere the first to bring the compounds 
prominently before the public. During the past year Mr. H. J. Webber, 
an assistant in the Division of Vegetable Pathology, engaged upon 
work in Florida, has used the resin washes with success in combating 
sooty mold of the orange and other citrus fruits. The sooty mold is 
a fungus which usually accompanies the attacks of certain insects. It 
is especially common in Florida, following the ravages of the white 
fly [Aleyrodes citri), and although not strictly speaking a parasite, it 
injures the host by interfering with transpiration and possibly also 
in other ways. 
Mr. Webber, in the course of his investigations in Florida, found that 
the wash could be very quickly prepared by certain modifications of 
the formula now generally recommended. The formula most generally 
used by the U. S. Entomological Division contains 20 pounds of resin. 
5 pounds of caustic soda (70 per cent), 2 J pints of fish oil, and 100 gal- 
lons of water. The resin and soda are broken up and, together with the 
fish oil are placed in a large kettle, sufficient water being added to cover 
them. The whole is then boiled for several hours, or "until the com- 
pound will mix properly in water without breaking up into yellowish 
flakes. n Mr. Webber uses 98 per cent granulated caustic soda and by 
this means is enabled to avoid the long-continued boiling. 
I have experimented with Mr. Webber's formula, and for a time was 
puzzled at the results obtained. It was found that by using the amount 
of caustic soda recommended by him a perfect compound was not 
obtained. That it was imperfect was shown by the flaky, soap-like 
masses floating in the clear solution. After considerable experiment- 
ing it was found that success in making the wash was dependent upon 
having just enough water and just enough caustic soda. By varying 
the amounts of either of these ingredients the preparation would show 
the undesirable flaky masses, which would not dissolve in cold water. 
However, if the full amount of water was added during the heating 
process there was no difficulty, but this is not desirable, as it is of con- 
siderable practical importance to have the wash as concentrated as 
possible. The perfect wash, although concentrated, should assimilate 
readily with cold water, forming a clear, brown solution when ready to 
apply to the plants. Without going into further details it may be said 
that as now worked out the formula for the stock or concentrated 
wash is as follows: 
Resin 20 parts = 20 pounds. 
Caustic soda (98 per ceut) 3 parts = 3 pounds. 
Fish oil 3 parts = 3 pints. 
Water 120 parts = 15 gallons. 
