METHODS OF REPRESSION. 81 
irritating effect which it has on tender membranes and surfaces. 
The finely powdered sublimate and the minute crystals when inhaled 
cause a severe irritation of the throat and nostrils, giving rise to 
sneezing and nasal discharges. The continued or careless handling of 
m freshly made ant tape will often have the same effect. It seems not 
^ improbable that the sublimate particles may have something of an 
irritating effect upon the sensory organs of the ants. The ants are 
7> * quick to detect and avoid corrosive sublimate even when it is in solu- 
tion and mixed with other substances. All attempts to poison them 
with this substance have been ineffectual, for they can not be induced 
i to partake of their most favorite foods when the latter contain the 
X„ poison in as weak a proportion as 1 to 500. 
In some of the tests made by the senior author the corrosive subli- 
H ' mate tape has been found to retain its efficiency for over 11 months in 
rooms where, except when the temperature was too low for insect 
activity, workers could be seen at all hours of the day and night. 
Our method of preparing the tape is first to heat corrosive sublimate 
and water in a porcelain or granite-ware vessel until the maximum 
amount is dissolved. This solution is allowed to cool to ordinary 
temperatures, filtered, and ordinary cotton or binding tape is soaked 
in it for several hours. The tape is then removed and pinned upon a 
wall to dry, after which it is ready for use. It is very important that 
no iron, tin, or steel come in contact with the solution, or with the 
tape itself after being prepared. The tape is effective for only a short 
time when used on metal surfaces. The extremely poisonous nature of 
corrosive sublimate must be continually kept in mind, both in the 
preparation of the solutions and tape and in the use of the tape itself. 
With this tape it is a comparatively easy matter so to isolate dining 
f tables, kitchen cabinets, refrigerators, etc., as to protect all food 
supplies in the ordinary residence. The same method is constantly 
used by confectioners in infested sections for the protection of their 
candy cases and supplies. 
EXPERIMENTS WITH FUMIGANTS AND CONTACT INSECTICIDES. 
Following the announcement by Mr. R. S. Woglum, 1 of the Bureau 
j of Entomology, in September, 1908, that he had succeeded in 
destroying colonies of other ants with a solution of potassium 
cyanid, considerable interest was aroused in the question as to 
i& whether the same method could be used with success against the 
Argentine ant. The senior author conducted a number of experi- 
B ments at Baton Rouge to determine this point, among which the 
L following illustrates the results obtained: 
i Los Angeles Times, Los Angeles, Cal., Sept. 20, 1908. 
75508°— Bull. 122—13 6 
