118 TRANSACTIONS OF THE [jAN. 4, 



ing to surrounding conditions. An inducing cause is necessary 

 to sturt decomposition, which is tiic function of some of the 

 fungi. 



DISCUSSION. 



Prof. Trowbridge remarked upon the great practical im- 

 portance of the study, and fully agreed with Mr. Dudley that 

 moisture must be present to start decay. "Wood in the roofs of 

 buildings had lasted over two thousand years, and was still 

 sound. The bridges put u[) by Towne, which gave him his 

 great reputation, were covered, the timl)3r kept dry, and some 

 of them were still in use, and sound. In re[)ly to iiis question, 

 whether there was any process which would preserve the timber, 

 Mr. Dudley said that could not be answered generally. Small 

 sizes of some kinds of timber had been preserved for some length 

 of time, but there was, as yet, no successful treatment for all 

 kinds of timber for all conditions of service. 



Prof. 'J^rowbridge said engineers in Eugland seemed to con- 

 sider creasoting tiie best treatment. 



Dr. Julien" said that these results explained at least one 

 source of the organic acids which do a geologic work in decom- 

 posing the rocks. He also noted the presence of mycelia in 

 vegetable debris upon and in the soil, as aiding in the i)roihic- 

 tion of these acids. 



He also queried whether there may not be two stages in the 

 decay of wood — the one initiated by the direct action of the hypht^ 

 of fungi; the other, the so-called "dry rot," in the presence of 

 a far less degree of moisture, insufficient for the further gi-owth 

 or even life of the mycelia, but sufficient for the continued 

 though slow action of an alkaline bacterial ferment. 



He suggested that the production of oxalic and other acids 

 might not depend wholly upon the growth of the mycelia, but 

 partly upon oxidation and direct chemical action (eremacausis), 

 due to admission of air permitted by the mycelium boring 

 through, and so oppning the tissue of the wood. Also that the 

 production of ozone by the oxidation of the resins in the wood. 



