MISCELLANEOUS INSECTICIDE INVESTIGATIONS. 39 
With lime-sulphur. — Triplumbio arsenate of lead combined with 
lime-sulphur solution again proved to have a slower toxic effect than 
either di or di and tri arsenates so combined. The triplumbic com- 
mercial No. 1 arsenate of lead was again less rapid as a poisoning 
agent than the commercial products of diplumbic compositions. It 
was found that the mixing of lime-sulphur and arsenate of lead results 
in a smaller consumption of foliage than when arsenate of lead is used 
alone. 
FIELD TESTS WITH APPLES. 
With lime-sulpliur. — Arsenate of lead consistently proved to be the 
most effective poison tested during the three years of experimentation. 
Triplumbic arsenate with lime-sulphur did not hold the codling moth 
in cheek quite as well as the ordinary commercial (diplumbic) arsenate 
of lead. Powdered arsenate of lead is equally as effective as the paste 
form for the control of the codling moth. 
LABORATORY AND FIELD TESTS. 
With commercial sodium sulpfiid No. 1. — The value of arsenate of 
lead is not decreased when combined with sodium sulphid ; in fact 
the sodium arsenate formed is more active as a toxin than lead 
arsenate. However, field experiments with apples show that this 
combination is impracticable, owing to the frequency of foliage injury 
due to the formation of the soluble sodium arsenate. 
With commercial harium tetrasulpliid. — Arsenate of lead mixed 
with barium tetrasulphid was used with satisfactory results for the 
control of the codling moth. This combination was found safe for 
use on apple foliage. 
With nicotine solutions and lime-sulphur. — Arsenate of lead may be 
mixed with nicotine solutions and lime-sulphur for the control of 
certain apple sucking and chewing insects, as well as fungous dis- 
eases. The mixing of these materials does not lessen their individual 
value and moreover may be applied to apple foliage with safety. 
With Icerosene emulsion and lime-sulpliur. — The combination of 
lead arsenate, kerosene emulsion, and lime-sulphur should not be 
used as an orchard spray, owing to the breaking down of the materials 
and the subsequent foliage injury. 
With fish-oil soap and lime-sulpliur. — The combination of arsenate 
of lead, fish-oil soap, and lime-sulpliur is not a compatible mixture 
for spraying purposes, since an insolublo calcium soap is formed. 
In our experience, any combination containing lime-sulphur and soap 
should not be used. 
ARSENATE OF CALCIUM. 
An effort was made to secure a satisfactory substitute for arsenate 
of lead, a compound which would be as efficient and at the same time 
less costly. With this object in view arsenate of calcium was used 
