378 



Philippine Journal of Science 



1919 



to time they were dug out for inspection. After eliminating the 

 infested blocks, the remainder were buried again. This ex- 

 periment was carried on for three years, starting on June 24, 

 1910 (Plate XI, fig. 1). Dates of inspection: July 4, 1911; 

 July 14, 1912; July 14, 1913. 



Table XLII.— Result of the experiment. 



Date of inspection. 



July 4, 1911 

 July 14, 1912 

 July 14, 1913 

 Do.... 

 Do.^._ 

 Do.— 

 Do — 

 Do.... 

 Do.... 

 Do.... 



Preservative. 



Wood-preservative A... 

 Atlas Preservative A .. 



Woodilin 



Woodol 



Carbolin l.„ 



Avenarius Carbolineum 



Stop-rot 



Carbolineum Atlas 



Crepit 



Wood-preservative B... 



Num- 

 ber. 



Bl<.-.;ks. 



Infes- 

 ted. 



Dry rot. 



No 

 dam- 

 age. 



Dam- 

 age. 



P.ct. 



100.0 

 71.4 

 75.0 



100.0 

 

 33.3 

 66.7 

 50. 

 75.0 



100.0 



Dry rot. 



P. ct. 

 



28.6 



25.0 

 

 

 

 

 



25.0 

 



As shown in Table XLII, none of the chemicals except Carbo- 

 lin, Avenarius Carbolineum, Stop-rot, and Carbolineum Atlas is 

 effective in preventing the attack of Odontotermes formosanus 

 and fungi as well. It is rather striking that the above-named 

 four chemicals, which are more or less effective, are the high 

 fraction of coal tar, mainly consisting of anthracene oil dis- 

 tilled at a temperature above 270° C. Moreover, the percentage 

 of damage is inversely proportional to the amount of the an- 

 thracene oil. 



Table XLIII. — Relative values of preventives and the percentage of anthra- 

 cene oil in each. 



Preventive. 



Damage. 



Anthra- 

 cene oiL 







Per cent. 



66.7 



50.0 



33.3 



0.0 



Per cent. 

 SO. 6 

 62.6 

 76.0 

 83.0 











It is evident, therefore, that the anthracene oil is a factor 

 in determining the effectiveness of those chemicals. 



