ISSC] NEW YORK ACADEMY OF SCIENCES. 117 



Tlie proof tlmt niitreiitcd wood is st.ible in some conditions is 

 very abundant. Tiniljer and plank in the roofs of foreign build- 

 ings are reported to bo in sound condition after a service of eight 

 to'ten centuries. Piles which were submerged in water and 

 mud are also reported sound after as long service. 



We have much older evidence of the preservation of vegetable 

 and animal tissue than that cont:iined in written I'ecords. I have 

 sections of coniferous branches supposed to have formed part of 

 tlie last dinner of the Mastodon, exluimed in .Jamestown, N. Y., 

 some years since, and the wood fibre is i)robably many thousand 

 years old, as the Mastodons have long since been extinct. Di'. 

 Hubbard exhibited here last winter a piece of the Siberian 

 mammoth skin, which must luive remained in the ice for thou- 

 sands of years. It was dried, and in this condition will last 

 indefinitely. Last week Dr. Hubbard gave me a piece to which 

 J have applied moisture and it is now undergoing decomposi- 

 tion — furnishing a rare morsel for countless bacteria. 



The evidence of the destructive influence of fungi is older 

 than that of the preservation of tissue. In the beautiful agatized 

 woods of the Triassic period, recently shown here, I find the 

 mycelia of the fungi, inducing their decay, preserved by the 

 infiltrating medium which agatized the woods. 



We daily see posts and telegraph poles, after three to four 

 years' service, decaying near the ground line, but above in better 

 condition. 



By comparing the difference of service, it can be seen how lit- 

 tle change is required to render unstable what would be stable 

 under other circumstances. In roofs there are dryness, circula- 

 tion of air, plenty of spores, and sufficient temperature to germi- 

 nate, but the necessary moisture is absent. In the case of sub- 

 merged piles, there is excessive wet, with insufficient temperature, 

 and exclusion of aii-, either to can-y spoi'cs or ])ermit them to 

 grow. In the case of the posts and telegraph poles, we have the 

 spores, the moisture, and the necessary temperature in summer 

 for germination, and decay ensues. 'J"iie last stated conditions 

 <ire those in which the great bulk of railway sleejiers are placed, 

 iind decay Avill result unless ])recautions are taken to prevent 

 it. It is not realized how thorough these precautions must be 

 \mtil thousands of decaying sleepers have been examined. In 

 many cases it seems as though each individual fibre must be pro- 

 tected, not only to prevent tlie germination of spores, but from 

 the stronger attacks of mycelia, which are in many old road- 

 I)eds. 



To obtain the best results, the kind oV wnod for the service 

 must be first considered. However, this general statement can 

 ^be made — the tissues of all wood remain sound or decay, accord- 



