Table II shows the toxic concentration of pyridine and quinoline when added to western yellow pine sawdust to be 2.45 and 1.08 per cent, respectively.It is evident that pyridine is much less toxic to Fomes annosus than quinoline. Owing to the low boiling point of pyridine, its high volatility, and low toxicity, it is obvious that this particular substance can play no important part in influencing the preservative properties of shale oil. Quinoline, on the other hand, owing to its high boiling point, low degree of volatility, and high toxicity, will undoubtedly influence the toxicity of shale oil to a high degree.