*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 appli- 
cation, as Dr. LeBaron long since showed that kerosene can safely be 
applied 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 at a minimum. 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 resume 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 can. 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 are in 
very thrifty condition. The applications were made at evening. On September 13, 
1881, 1 applied to twenty-five young trees in my own grove a wash consisting of lpint 
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 
a very hot, clear day. Tree A stood in the shade of an oak tree, B in the sun. Sep- 
tember 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 A and 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 possible 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. Every orange 
grower knows how difficult it is 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 
