The Biology of Polyporus Pargamenus Fries 155 
The one from the infiltrated wood was of the deeper hue. 
A small quantity of each extract when heated upon a plati- 
num wire burned readily with a pale yellowish flame, emit- 
ting small quantities of a whitish vapor and giving off odors 
apparently peculiar to these substances. The extract from 
the infiltrated wood, when burned upon a platinum wire, left 
a dark brown, bead-like residue, while the extract from the 
sound wood, when treated in like manner, burned completely. 
Both alcoholic extracts were insoluble in cold or boiling 
water, concentrated hydrochlorie acid, ether, petroleum ether, 
chloroform, carbon bisulphide, and carbon tetrachloride. 
Their specific gravities are indicated by the fact that they 
were not suspended in or floated upon any of the organic 
solvents tried, of which the heaviest, carbon tetrachloride, 
has a specific gravity of 1.63. Neither, however, sank in 
concentrated sulphuric acid, whose specific gravity is 1.84. 
Both alcoholic extracts, however, were soluble in cold abso- 
lute alcohol, acetone, and a 10 per cent solution of sodium 
hydroxide. When the last-named solution was neutralized 
with sulphuric acid the extracts, in both cases, were pre- 
cipitated — that is to say, they were insoluble in the exactly 
neutral sodium sulphate solution thus prepared. Both alco- 
holic extracts were soluble to a brown solution, but dissolved 
more slowly and without carbonization, when shaken in cold 
concentrated sulphuric acid. The alcoholic extract from the 
infiltrated wood was soluble in cold ammonium hydroxide, 
whereas that from the sound wood was soluble only by heat- 
ing the reagent to boiling. When hydrochloric acid was 
added to the ammoniacal solutions until they were slightly 
acid both extracts were precipitated, leaving the solutions 
colorless in both cases. 
None of the treatments thus far applied have secured a 
separation of the substances peculiar to the infiltrated wood 
and giving to it its distinguishing color. The solubilities 
and other properties of the respective extracts from the 
decayed wood indicate that a portion of the carbohydrate 
substance, particularly the hemicellulose xylan, had been con- 
verted into humie substances of two principal groups: First, 
