Clroular 21 - Inseoticldes and Subaldi&ry Matvriftls 20 
^Available on contract: See Class 59, 
Greneral Schedule of Supplies, Procurement 
Division, Treasury Department. 
COAL TAR PLASTIC C2ICENT 
One of the procedures in the control of 
termites is the sealing of expansion joints in 
floors and spaces around pipes or steel pene- 
trating floors and walls with coal tar plastic 
cement. 
This material is composed of refined 
coal tar fluxed to the proper consistency with 
mineral fillers such as asbestos fibre and 
slate flour. In construction work it is used 
for sealing flashings and joints in roofing and 
in general roofing repairs. 
Coal tar plastic cement is procurable at 
a cost of $3.25 in 5 gallon cans. 
For manufacturers and distributors see 
numbers 63, 86, 9^, 95, and 106 of list at end 
of this circular. 
COCONUT OIL SOAP (LIQUID) 
Liquid coconut oil soap (40 percent) is 
useful as an emulsifier in preparing a pyrethrum- 
oil emulsion for use on fresh water or water 
of less than 5 percent salinity as a larvicide 
for killing mosquito larvae. This soap is^ 
diluted with water and the pyrethrum extract 
added. The emulsion is sprayed on the surface 
of mosquito breeding areas such as ponds, marshes, 
and pools of water. 
^.^"^^^ 
