42 BULLETIN 737, U. S. DEPARTMENT OF AGRICULTURE. 
order to avoid sweating which ordinarily would occur upon re- 
moval from cold storage. When removed from cold storage it 
was placed in a dry room for several hours, then placed in the 
humidor or storage room at the cigar store with the control or check 
packages. At frequent intervals the treated tobacco was compared 
with check tobacco by Mr. J. M. Holt, a tobacco expert of Richmond, 
Va., and the writer. The tobacco put in cold storage seemed in per- 
fect condition in every respect, and could not be distinguished from 
that which had been kept at the cigar store. 
ALTERNATIONS OF HEAT AND COLD. 
The alternation of a low temperature with a comparatively high 
temperature is apparently more effective on the tobacco beetle than 
is a single exposure to cold. During the course of cold-storage in- 
vestigations at Richmond, Va., in 1914, two lots of badly infested 
smoking tobacco were put in cold storage for 2 days at temperatures 
ranging from 14° to 16° F. Lot A was not removed from the stor- 
age room, whereas at the end of 24 hours lot B was removed and 
kept in a warm room for 24 hours, then put back in cold storage for 
a further period of 24 hours. On March 22, 2 days after treatment, 
both lots were examined and no live stages of the beetle were found 
in lot B. In lot A about 90 per cent of the different stages were 
dead. The tobacco used in the experiments was kept until August 
28, 1914, and upon examination lot A was found heavily infested 
whereas lot B was uninfested. 
HIGH TEMPERATURES. 
EXPERIMENTS WITH DRY HEAT AS A MEANS OF STERILIZING TOBACCO—TESTS IN 
TOBACCO FACTORIES. 
Two series of tests were made, one at Richmond, Va., in a factory 
where smoking tobacco is manufactured, and the other at New 
Providence, Tenn., in a factory in which special processes are used 
in the preparation of leaf tobacco for export to Africa. 
Excellent facilities were secured for determining the effect of high 
temperatures on different stages of the beetle, and for determining 
to what extent the tobacco is sterilized by the various processes of 
manufacture. It was found that in these factories the temperatures 
reached were sufficiently high to kill all stages of the beetle, rein- 
festation depending on methods of handling, packing, or storing the 
manufactured product. 
At Richmond, Va. (May, 1915), large numbers of eggs of the 
tobacco beetle on leaf tobacco and in cells on microscope slides, pupz, 
adults, and newly hatched and mature larve were placed in boxes 
