METHODS OF REPKESSION. 81 



irritating effect which it has on tender membranes and surfaces. 

 The finely powdered subhmate 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 

 freslily 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 

 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 

 to partake of their most favorite foods when the latter contain the 

 poison in as weak a proportion as 1 to 500. 



In some of the tests made by the senior author the corrosive subli- 

 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 j)orcelain 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 

 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,^ of the Bureau 

 of Entomology, in vSeptember, 1908, that he had succeeded in 

 destroying colonies of other ants with a solution of potassium 

 cyanid, considerable interest was aroused m the question as to 

 whether the same method could be used with success against the 

 Argentme ant. The senior author conducted a number of experi- 

 ments at Baton Rouge to determuie this pomt, among which the 

 following illustrates the results obtamed: 



1 Los Angeles Times, Los Angeles, Cal., Sept. 20, 1908. 

 75508°— Bull. 122—13 6 



