February,’18] LOVETT: spreaders for arsenate sprays 
67 
to be applied as a finely divided fog or mist like spray, indicate, in 
our preliminary tests, a very distinct advance in effectiveness. 
Of equal importance in this regard is the development of an efficient 
spreader which may be added to the arsenate solution. We believe 
that if a satisfactory spreader can be developed it will be possible to 
get very effective codling moth control with a dilution of 1 pound of 
arsenate to 100 gallons of solution. It is a matter of common experi¬ 
ence when checking on a sprayed plot for the thoroughness of applica¬ 
tion to judge largely by the half circles and blotches of dried arsenate 
deposited more or less irregularly over the sprayed surface. Our con¬ 
ception of an efficient spreader is some material which allows the drop¬ 
lets to so spread out and join one another as they dry that the arsenate 
finally rests as an even, regular, inconspicuous covering affording a 
perfect and equal protection for every surface. 
Suspension Tests 
The surface tension and specific gravity are probably factors of 
importance in determining the value of a spreader, but so far the corre¬ 
lation of each to the other has not been determined and does not appear 
to be in a direct proportion. The ability of a liquid to hold arsenate 
in suspension does appear to be a very fair indication of its ability as a 
spreader, however. The materials tested, the dilutions and results 
are given in Table No. I. 
One thousand cubic centimeters of each solution was taken, cylin¬ 
ders of uniform size and 1000 cc. capacity were used, and to each solu¬ 
tion was added 5 grams of acid lead arsenate; the cylinders were thor¬ 
oughly and uniformly agitated and the arsenate allowed to settle. 
Readings were made at the end of 5 minutes, 10 minutes, 2 hours and 
6 hours. 
Table I—Suspension Tests 
Material 
Dilution* 
Readings of Settled Arsenate 
5 Min. 
10 Min. 
2 Hrs. 
6 Hrs. 
Remarks 
Sage tea. 
1-1000 
1 cc. 
1.2 cc. 
3.6 cc. 
6 cc. 
Good 
Sage tea. 
5-1000 
.7 cc. 
.9 cc. 
2.8 cc. 
4.8 cc. 
Very good 
Glue. 
1-1000 
.8 cc. 
1 cc. 
3.4 cc. 
6 cc. 
Good 
Glycerine. 
5-1000 
.6 cc. 
.9 cc. 
4.2 cc. 
7.1 cc. 
Good 
Gelatine. 
1-1000 
.5 cc. 
.6 cc. 
2 cc. 
3.1 cc. 
Excellent 
Sugar. 
5-1000 
7.7 cc. 
9 cc. 
All down 
More rapid than water 
Honey. 
Gum Tragacanth. 
5-1000 
1-1000 
3.8 cc. 
6.8 cc. 
4 cc. 
All down 
8 cc. 
All down 
Poor 
No good 
Fish oil soap. 
1-1000 
2.5 cc. 
3 cc. 
4.8 cc. 
All down 
Material flocculent 
Casein-lime. 
1-1000 
1 cc. 
1.6 cc. 
3.2 cc. 
5.8 cc. 
Good 
Resin soap. 
Water. 
5-1000 
3 cc. 
6 cc. 
3.8 cc. 
8 cc. 
5 cc. 
All down 
All down 
Poor 
* The dilution figures refer to the number of grams or cubic centimeters of material to 1000 cc. of water; 5 grams of 
acid lead arsenate was added to each solution. 
Some of these materials were run a second and even a third time, 
