31 
All the sulphur and half of the lime are placed in a kettle and 33 
gallons of water added, after which the contents of the kettle are boiled 
briskly for about 1 hour; the solution will then be of a very dark brown 
color and having a reddish tint. All of the salt is added to the remain- 
ing 21 pounds of lime and the latter slaked, after which this slaked 
lime and salt are added to the above described sulphur and lime solu- 
tion and the whole then diluted with a sufficient quantity of water to 
make 100 gallons; this is then strained, after which it is ready to be 
sprayed upon the trees. 
This does not form a perfectly liquid solution but contains a consid- 
erable quantity of undissolved sulphur and lime, which soon settles to 
the bottom unless the solution is stirred almost constantly while being 
sprayed on the trees. It is therefore somewhat of the nature of a thin 
whitewash, and the trees sprayed with it have the appearance of hay- 
ing been whitewashed. On the 26th of November, at 12:45 p. m., sun 
shining, light breeze, I sprayed a pear tree with a wash made according 
to the above directions, the tree being very thickly infested with the 
San José scale. January 15 I found 14 living San José scales on this 
tree, and on the 23d of April I found several more; on the 11th of 
June I found on this tree a Black scale (Lecanium olew Bernard) con- 
taining healthy eggs. 
I also tested this wash in the following proportions ; 
Sm Tere elo nts retctn stein oeiniele's orale ats, is) Aeleedajsieriseins Bene sae <= pounds.. 50 
ILA Behe Seca pec neO Oberon BOSH OSS Dot SORaonE NO Ee eae HorSpetnas do... -63 
Sli ocano os6G00 sso S6eneedan esooDd bOOD0e RobSSdioDeses caso naeE CWscse Bi 
Wyiiterzen Gum bh tonm ale ceca oss seisinisioreielao ae iaierte sicialcl ae gallons.. 100 
This was applied to a pear tree at 1 p. m., November 26, sun shining, 
light breeze. On January 15 I found 6 living San José scales on this 
tree, and on the 23d I found several more. 
At the time of making these tests there were several green leaves on 
each of these trees, but all of these were killed by the washes. The 
trees otherwise were not apparently injured, and in the following spring 
started into a vigorous growth which was continued throughout the 
summer. These trees were not over 10 feet tall, and were very thor- 
oughly sprayed, so if seems quite certain that every scale insect located 
upon them must have been covered with the wash. 
The philosophy of this wash is not at present clearly understood. 1 
seems very probable however that the product of the lime and sulphur 
(bisulphide of lime, CaS.) furnishes the insecticidal property, and the 
presence of the salt and slaked lime simply imparts permanency to the 
-wash. I made quite a series ef experiments with the above-named in- 
gredients, with a view of ascertaining which of the ingredients were 
really insecticides, but these experiments have thus far resulted nega- 
tively. The following is a brief account of these experiments : 
SAL1?.—Experiment 229: Table salt, 19 pounds; water, 100 gallons. 
I simply dissolved the salt in cold water and then sprayed the solution 
