THE TOXICITY TO FUNGI OF VARIOUS OILS AND SALTS. 29 



The three lower boiling fractions of coal-tar creosote are highly 

 toxic, exceeding the creosote itself. Fraction IV is only about one- 

 sixth as toxic as creosote. Fraction V, consisting of the last heavy 

 residues, of which only 10 per cent distills below 320° C, is extremely 

 low in toxicity, with a killing concentration of about 33 per cent. 



Wood creosote, derived from the destructive distillation of Douglas 

 fir, compares very favorably with coal-tar creosote, notwithstanding 

 its water content of over 8 per cent. 



Hardwood tar shows moderate antiseptic properties, proving about 

 one-half as toxic as the softwood creosote. 



The two carbolineums are much less toxic than the creosotes tested. 



Water-gas tar distillate of low specific gravity appears to be slightly 

 less toxic than coal-tar creosote, while the heavier distillate, repre- 

 sented by United Gas Improvement Co. 1.07 oil, is so low in toxic 

 properties as to appear to be of little value in wood preservation. 



The secret product None-Such Special appears to be more nutrient 

 than antiseptic to fungi, so far as these tests indicate; however, the 

 physical properties of the substance when injected into wood may be 

 such as to exclude fungous growth and thus to substantiate the 

 claims made for it. Durability tests on treated wood are highly 

 desired. 



Zinc chlorid has a killing point almost identical -with coal-tar 

 creosote. 



Table II also shows that of 14 preservatives tested against Fomes 

 pinicola 8 totally inhibit growth below 0.5 per cent, 2 between 0.5 and 

 1 per cent, 1 at about 7.8 per cent, and the remaining 3 require over 

 40 per cent. 



Sodium fluorid and coal-tar creosote Fractions II, III, and IV are 

 all extremely toxic to this fungus, the killing points being almost 

 identical. 



Coal-tar creosote Fraction I and wood creosote are about three- 

 fourths as toxic as the above; Avenarius carbolineum is about one- 

 half as toxic. - 



Zinc chlorid hi the Fomes pinicola list stands only tenth in efficiency, 

 whereas in the F. annosus list it stands in fifth place. 



The last four preservatives show very low antiseptic properties 

 toward Fomes pinicola, as they did toward F. annosus. 



By comparing the behavior of the two fungi toward the same 

 chemical substances a marked difference will be observed. With the 

 exception of zinc chlorid and copperized oil, Fomes annosus is a far 

 more resistant organism than F. pinicola, the ratio running as high 

 as 26 to 1 in the case of Fraction IV of coal-tar creosote. 



It has often been noted during the course of the experiments that 

 Fomes annosus, after a considerable lapse of time, can accommodate 

 itself to rather high concentrations of certain preservatives. Its 



