342 Philippine Journal of Science 1919 
termite, since the foundation timbers are laid in contact with the 
ground. 
From the point of view of economy, it is impossible to elim- 
inate such nonresistant timbers from Japanese buildings. 
Therefore, a discovery of a new method of building construction, 
by which the attack of the termite can be absolutely prevented, 
becomes an important problem. 
As a result of bitter experience during the last twenty years, 
the method of constructing buildings and the treatment of 
nonresistant timbers have been greatly improved. As it is 
practically proved that the termite-proof building construction 
that has been recently adopted by the Government of Formosa 
is somewhat satisfactory, I, having been chiefly concerned with 
the investigation, wish to explain the method in detail. 
Disinfection of the ground. — Not only is Coptotermes formo- 
sanus widely distributed throughout Formosa, but it occupies 
the whole ground densely; so that, as a first step in erecting 
a building, it is absolutely necessary, to destroy the pest, to keep 
the site free from the source of the damage. For this purpose, 
heavy oil of petroleum, creosote oil, or Termitol (a mixture of 
heavy oil of petroleum and cresol) is sprinkled over the whole 
surface of the site, using 1 gallon (about 4 liters) of the fluid 
to 6 square feet (about 0.6 square meter) of area. 
These fluids are nonvolatile at ordinary temperature and in- 
soluble in water. They are effective for a long time, as they 
remain in the ground unchanged. 
Footings. — To keep a wooden building free from termites, 
care should be taken not to use timbers in contact with the 
ground. To do this, it is necessary to use bricks and concrete 
in footings, even in the case of a wooden building. 
The termite-proof concrete layer. — In order to prevent the 
entering of the termite, it is necessary to disconnect the upper 
parts of buildings from the soil. After the footings have been 
completed, a layer of cement concrete about 6 inches (about 15 
centimeters) thick is spread over the whole area of the site at 
ground level, the edges being extended about 3 feet (about 1 
meter) beyond the external walls of the building. Along the 
edges small drains are made, surrounding the whole concrete 
layer. Then the entire surface of the layer is covered with a 
thin stratum of cement mortar to fill up all the pores and cracks 
(Plate IX, fig. 1). 
To reach the building, termites must either penetrate the 
concrete layer or cross the drains from the outside. It is proved, 
