-46- 
The bio-assays -"ere made "ith 5-day-old houseflies, caged in 
5-inch by 5-inch, cylindrical, all-^ire cages, using approximately 
100 flies to the esse. Each cage "as separately exposed to the 
same amount of finely atomized spray or fog from which the larger 
droplets had been removed, by using an L-shaped -nine, 6 inches in 
diameter and 1 foot long on each side of the elbo"7, mounted with 
one side of the L in a vertical position. The cage of flies "as 
then suspended in the top of the upright pipe and the atomizer "2s 
placed at the other end of the L. Five cubic centimeters of the 
diluted ester of the extract was then atomized into the -nive at the 
bottom end, producing a highly dispersed, smokelike fog, -hich -"as 
driven evenly throughout the cege. The cage ^as then removed and 
set aside, for 24 hours, when the number. oC ll d.eedJ l "as .determined — 
the term "dead" including flies th= ; t were paralyzed and unable to 
feed after 24 hours. 
PierpOnt (235 ) in 1939 reported that the insecticidal action 
of solutions containing 50 and 100 gig. of rotenone, respectively, 
per 100 cc. and 7.5 percent of sefrol in a petroleum-oil base res 
increased by the addition of 2.5, 5.0, 7.5, and 10.0 percent of 
D. H. S. Activator (ethylene glycol ether of pinene) . The increases 
vere less then with pyrethrum fly sprays, aoproximatir.g 5 percent 
for each 2.5 percent of activator added. The 24-hour mortality for 
rotenone fly sprays tos increased by the addition of D. H. S. Acti- 
vator, without any significant reduction in the 24-to 48-hour 
mortality characteristic of them. As rith pyrethrum fly sprays 
D. H. S. Activator reduced the knock-do^mi time of the rotenone 
-safrol combinations in relation to the amount added: that is, the 
more Activator, the quicker the knock-dom. Fly sprays of rotenone 
(100 mg. per 100 cc.) and sefrol (7.5 percent) in a petroleum-oil 
base and these same snrays containing various amounts of B. H. S. 
Activator were stored in airtight tin cans at room temperatures 
ranging from 70°-80° F. and likewise exposed to heat ' (a constant 
temperature of from 100°-105°) for 8-1/2 months rithout any signi- 
ficant loss in toxicity or reduction in the activation effect. 
The loss in the toxicity of fly sprays containing rotenone, 
safrol, and I). H. S. Activator, "hen exposed to sunlight and light 
in flint-~lass bottles, is correlated with color changes and pre- 
cipitation. Although disintegration apparently takes place more 
rapidly than with the rotenone and safrol alone, the Activator 
functions in maintaining nuch sprays at a relatively hi ~h toxic 
level. Ethylene glycol ether of pinene (D. H. S. Activator) is an 
effective activator for both pyrethrum and rotenone and can be 
safely and economically included in commercial fly sprays. 
Sievers and Sullivan (251) reported in 1939 that they used the 
housefly in the turntable method for evaluating different extracts 
of the root of devil' s-sho'estrings ( Tephrosia virginiana ). Acetone 
and chloroform '-ere equally effective in extracting the active princi- 
ples, and heating the extracts d-d not decompose thi 
Sullivan, ticGovran, Fairs, and Goodhue ( 267 ) in 1939 reported 
that the smoke farmed by epreying a solution of rotenone in safrol 
