- 
6 ORANGE TREE AND COTTON PLANT. 
tree will withstand a thorough drenching with the pure oil. Again, 
much will depend upon the condition of the tree and the time of applica- 
tion, as Dr. LeBaron long since showed that kerosene can safely be ap- 
plied to apple trees in the spring of the year (Second Illinois Report, 
pp. 114, 115), or during the season of rapid growth. Again, the con- 
dition of the atmosphere will have much to do with the results, and the 
injury by kerosene will be greater during cool, damp weather, when 
evaporation is ataminimum. The fatal results in California may also 
be due to the large quantity used and the coarse methods of applica- 
tion, for Mr. Chapin’s report shows that in most of the experiments it 
was applied undiluted, in coarse spray, while the quantity is not stated. 
As two years have now elapsed since Mr. Hubbard began the use of 
kerosene emulsions, we recently sent him a copy of Mr. Chapin’s report, 
with the request that he give us a résumé of his views, and particularly 
requested him to examine the trees that had been first treated with kero- 
sene. We give herewith his report: 
I have never seen any serious injury from applications of even pure kerosene. In 
1880 one of my neighbors treated some very young orange trees for Lecanium scale by 
pouring the oil upon them from an oil cau. The trees were not in very bad condition 
at the time, and did not appear to suffer any injury at all, and at this date they arein 
very thrifty condition. The applications were made at evening. On September 13, 
1881, I applied to twenty-five young trees in my own grove a wash consisting of 1 pint 
kerosene emulsified imperfectly with 1 quart fresh milk, and diluted with 5} quarts 
water. The emulsion (No. 1) was very imperfectly united, and most of the oil rose to 
the surface, and as the wash was applied with a brush, the first trees washed received 
a large amount of pure kerosene upon the trunks, branches, and in many cases upon 
the leaves. This application was made in the afternoon (2 p. m. to 6 p. m.) of a very 
hot, clear day. The trees so treated received not the slightest harm, and at this date 
are among the finest in the grove, and most of them have quadrupled their size within 
the year. About the same date (September 14) I made, as a test, an application to 
two young orange trees of a very unstable mixture: of kerosene, 1 pint; of milk, 2 
fluid ounces; of water, 2 ounces; which, when diluted, separated and floated on top. 
The mixture was applied with a brush, and the oil could be seen to penetrate the 
leaves, so that they appeared greasy and translucent. Applied between 12 m. and 1 
p. m., on avery hot, clear day. Tree A stood in the shade*of an oak tree, B in the 
sun. September 16, 1881: B, old, devitalized leaves loosened or fallen; A, no leaves 
loosened or fallen. September 20, 1881: B has dropped its leaves badly ; A has dropped 
fewer leaves. December 17, 1881: both trees apparently cleared of living scales, 
February 14, 1882: trees pushing out vigorously; no apparent difference in condition 
of Aand B; no living scales can be found. To-day, November 9, 1882, these trees are 
in splendid condition, and have made nearly, if not quite, the maximum growth possi- 
ble in the year. In these cases the effect of the kerosene has been simply to remove 
the scale; the rest is due, of course, to cultivation. 
Another test, which I intended to be crucial as to the effect of diluted kerosene wash 
upon the roots of the orange, was made at the same time, September 14, 1881. _ In this 
experiment I selected a very small, two-year-old, budded orange tree, which had made 
no growth during the year, was starved and hide-bound, and stunted. Hvery orange 
grower knows how difficult itis to start such a tree into vigorous growth. I dished 
the earth around this tree and poured a gallon and a half of kerosene wash, contain- 
ing 1 pint of the oil in emulsion with milk, into the cavity about the base of the 
tree, so that the whole of it soaked into the sand on and about the roots. The tree 
Mem ot ak 
