17 



tion.s the wall.s of the wood cells arc foiind to be very nuu-h thinner. 

 They are badly curved and twisted l)y the knife and have lost all stiff- 

 ness and elastieit}'. A thin section can be pushed about with a needle 

 as if the cells were made of pieces of flexible wire jointed at the points 

 of union. Here and there the Avails are perforated, showing where 

 the hj^pha? of the fungus passed through. The t-heniical l)ehavior of 

 the walls shows that the cellulose has been removed almost entirely. 

 When dilute KOH is added they swell to several times their normal 

 size and dissolve in part. Acids precipitate a ])rown flocculent sub- 

 stance from such a solution, hot nitric acid dissolves the wood i-om- 

 pletely, and the addition of excess of water produces a deep orange 

 precipitate, all of which reactions indicate great chemical changes. 

 The three lamelUe of the cell wall may be seen, but they have shrunk, 

 and the pits in the tracheids show four cracks, about 45 degrees apart, 

 apparently brought about by shrinkage due to drying. Cellulose 

 stains do not react even after treatment Avith KOIT. "With phloroglu- 

 cin and HCl the wood turns red, and Avith thallin yellow. In certain 

 cells red broAvn masses of a substance are found which are unafl'ected by 

 acids or alkalies. They turn black Avith osmic acid or iron salts, indi- 

 cating that they are prol^ably one of the tannins. As these cells cor- 

 respond somewhat Avith the position of the resin cells, it is possible 

 that the brown substance is a derivative of the resin. 



Continuous extraction of tineh' rasped cedar Avood was made Avith 

 absolute alcohol for six hours, using a Soxhlet's extractor, and finely 

 powdered charred Avood Avas similarly treated. The resulting yelloAv 

 liquid Avas distilled until a sirupy liquid was obtained, and from this 

 the alcohol was allowed to eA'aporate slowly. The substance that 

 remained was red brown and could be readily broken into small pieces 

 with bright fracture. It was insoluble in water, readily soluble in 

 alcohol, and with phloroglucin and hA'drochloric acid gaA'e a red color 

 identical with that obtained when wood fiber is treated with these 

 reagents. The quantities of this substance obtained from charred 

 wood and from normal wood were about equal. It was belicA^ed that 

 the substance obtained Avas probabh" the bearer of the properties Avhich 

 had heretofore been A^aguely regarded as lignin substance, but it 

 proved to be identical Avith Czapek's hadromal.^ Czapek obtained the 

 same b}^ boiling with zinc chloride and extracting the wood liber thus 

 treated with benzol. In the experiments here discussed the alcohol 

 extraction proved sufficient. 



It is evident that if the hadromal be the substance which gives the 

 wood character to cellulose fiber, all fungi attacking wood do not 

 destroy this compound, for in the brown disease of the cedar the 

 hadromal is as abundant as in the normal wood. The same may be 



^ Czapek, 1. c;. 

 25257— No. 21 2 



