24 BULLETIN 1232, U. S. DEPARTMENT OF AGRICULTURE. 
mound nests or which have underground galleries with well-defined 
openings. This chemical is a coal-tar product made by combining 
benzol and chlorine gas. Crystals could be placed in the openings 
of the nests or mounds and thus kill subterranean termites. How- 
ever, where a large number of termite mounds occur on land intended 
for -cultivation, the land can be cleared by the use of steam shov- 
els or by exploding the mounds with dynamite and crushing them 
by a heavy gasoline caterpillar tractor. The soil can then be 
sprayed with sodium cyanid to kill the termites, using 160 pounds 
of granular sodium cyanid per acre with 12.000 gallons of water, as 
recommended for the Japanese beetle (PopUlia japonica Xewm.). 
or quicklime, wood ash, or lye used. 
Species in the family Kalotermitidae probably can be practically 
controlled by the use of dry heat. In the attic of the Royal Palm 
Hotel, a large, high, frame structure at Miami. Fla., the temperature 
becomes very high, due to the subtropical heat and also to the fact 
that the sun's rays beat down on the roof; the temperature in the attic 
was from 17° to 24 c F. higher than the maximum temperature re- 
corded by the United States Weather Bureau. Oak and maple 
furniture infested with the destructive West Indian termite Crypto-* 
termes brevis Walker, which had been removed from guest rooms 
and placed in this attic directly under the roof, contained no living 
termites when examined in the latter part of January and early part 
of February. 1922. by T. E. Snyder. Small piles of pellets under 
this furniture indicated that the termites had continued to work in 
the infested furniture for a short period after having been removed 
to the attic, where undoubtedly the temperature became too great 
even for a termite that normally lives in hard dry wood. i. e., in 
wood which probably contains normally only about 10 per cent of 
moisture. 
O'Kane and Osgood (5) were successful in killing the earth-in- 
habiting termite Reticuliterrnes flavipes Ivol. which was infesting the 
woodwork of a large hospital at Dover, X. H., by the use of supple- 
mentary steam piping and maintaining a temperature of 185° F. for 
24 hours. 
Fumigation with hydrocyanic-acid gas will kill species of Kalo- 
termitidae infesting woodwork of buildings or furniture. Twelve 
ounces of sodium cyanid per 1,000 cubic feet was successfully used 
in killing Cryptotermes brevis Walker infesting woodwork and fur- 
niture in case of the Royal Palm Hotel at Miami, after the building 
had been sealed ; the gas remained in the building for about 48 
hours. 
In order to kill termites of the family Kalotermitidae which 
work in dry wood and have no connection with the ground, various 
mixtures can be used. A 20 to 30 per cent solution of paradichloro- 
benzene in kerosene (or orthodichlorobenzene. a similar chemical) 
can bo used effectively. 
The infested wood is saturated with this liquid by swabbing it 
with a mop. Several treatments may be necessary to enable the 
chemicals to penetrate the wood and kill the insects therein. A 
poisoned kerosene-emulsion mixture can be similarly used by dissolv- 
ing 1 ounce of sodium arsenite in each gallou of the water used for 
diluting stock mixtures of kerosene emulsion or miscible oil. 
