PERCENT DEAD PERCENT DEAD 
August, ’23] FULTON: POISONING EUROPEAN EARWIGS 375 
TIME BY DAYS 
Vz Wz 2'/z 3'/a 4Vz 5Zz 6Vz 7Vz t'A 9Vz 
Chart I. Curves showing toxicity of sodium fluoride, arsenious oxide, sodium arsenate and calcium 
fluoride, for European earwig. 
