DISEASES OF TAXODIUM AXD LIBOCEDRUS. 



usually more numerous at the lower-end of the cells. When 

 KOH is added the whole mass dissolves slowly, melt- 

 ing away like wax; the tracheids become filled with the 

 red-brown solution. By treating finely divided wood with 

 dilute KOH this substance can be extracted in quantity. 

 If the potash solution is neutralized with dilute HC1, a red- 

 brown flocculent gelatinous precipitate is formed slowly, 

 which gradually settles to the bottom. When dried it re- 

 sumes the appearance seen in the tracheids. In mass it is 

 reddish-brown, soft, tasteless and odorless, insoluble in 

 alcohol, ether, chloroform, acetone, turpentine, etc., but 

 very soluble in alkalies, KOH, NaHPO*, etc., and can be 

 reprecipitated from such solutions by acids. Because of 

 its peculiar physical and chemical properties the sub- 

 stance is classed among the humus compounds. This 

 humus compound, as it will be designated, was evi- 

 dently at first in a liquid condition, as it fills the cells 

 so evenly. Furthermore, wherever mycelium occurs, 

 this is coated with a layer of the compound, so that 

 the walls of the hyphae look brown and show several con- 

 tour-lines. Wherever there is any sign of decomposition, 

 there this product appears immediately. It is at first seen 

 in the medullary rays, filling the cells and obscuring their 

 contents so that nothing can be distinguished in the cells. 

 The brown contents of the rays extend out through many 

 annual rings from the initial point of decay. On several 

 occasions trees were found with exceptionally large quan- 

 tities of this material. In these trees the cavities or holes 

 had a brown powdery mass lying loosely within, but the 

 bounding walls had a thick coating of the brown substance. 

 It was quite soft, broke readily with a shining fracture, was 

 non-elastic and dissolved readily in alkalies, in fact agreed 

 so closely with substance already found in the tracheids as 

 to leave no doubt as to their being one and the same sub- 

 stance. The finding was of value as it was possible to 

 trace the origin of this compound directly, which was not 



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