containing ethyl hexanediol, dimethyl phthalate, and Indalone. With 
ethyl hexanediol, dimethyl phthalate, and calamine the average repellent 
time was more than twice that obtained in concurrent tests with undiluted 
ethyl hexanediol. In two series of tests, one with dimethyl phthalate and 
one with the mixture 6-2-2, the addition of calcium stearate as a thickener 
to creams containing bentonite extended the repellent time. The solid 
repellents butyl sulfone, N-ethylacetanilide, and N-propylacetanilide 
gave considerably longer repellent times than the standard. 
Cold creams and vanishing creams containing 30 percent of the 
repellents 2-(2-cyclohexyloxethoxy)ethanol; 3-(2-cyclohexyloxy-1- 
methylethoxy)-2-propanol; ethyl hexanediol; and 2-/2-(3,3,5-trimethyl- 
cyclohexyloxy )ethoxy/ethanol were found less effective than the undiluted 
repellents. 
The repellent time of a number of the better repellents was reduced 
by the addition of a volatile solvent, but the reduction was not in propor- 
tion to the dilution (table 7). N-Ethylacetanilide was the only solid 
material that gave more than 100 minutes’ protection. 
When the repellents were mixed with nonvolatile solvents, the repellent 
time was also reduced. Occasionally a few tests with such materials would 
give a long repellent time. However, the results were not consistent; so 
only screening-type tests were made with these materials. 
Some tests were made with materials added to dimethyl phthalate. 
The addition of 2 percent of camphene, 10 percent of a crude alkaloid of 
Haplophyton, 5 percent of aluminum chloride, or 10 percent of calcium 
chloride caused little or no increase in repellent time. The last two 
compounds are said to reduce sweating. 
A number of preparations containing ethyl hexanediol, dimethyl 
phthalate, or Indalone, and some unidentified aromatic substances in 
powder, petroleum, or beeswax base sent by various agencies were 
tested in the field. Only the powder-base creams and a beeswax-base 
cream containing ethyl hexanediol or a mixture of this repellent and 
dimethyl phthalate gave repellent times that compared favorably with 
the undiluted repellents. A proprietary product containing 50 percent 
of the acetate of 2-(2-butoxyethoxy)ethanol was found to be only slightly 
less effective than this compound undiluted. 
Aedes sollicitans 
Of the 12 materials tested against sollicitans, 2- /2- (2-ethylhexyloxy)- 
ethoxy/ethanol, 2- /2- (alpha- a eingibenzvioxy)eiioxay/eoenol and dl- 
dibutyl malate were effective for more than 5 hours (table 8). Dimethyl 
phthalate and Indalone were equally effective against sollicitans as against 
taeniorhynchus. A proprietary material containing 50 percent of 2-(2- 
butoxyethoxy)ethyl acetate was found in 5 tests to be equally as effective 
as the undiluted material. 
