BULLETIN OF THE BUSSEY INSTITUTION. 447 
to act upon the cellulose in the wood. It was noticed, for example, 
that even 30 c.c. of the strong acid made a pasty mass with the 
residue, and that only a small part of the residue was blackened. 
Hence, the residue from this treatment with strong acid was dried 
carefully and again mixed with a new portion of the strong sul- 
phuric acid. In this case the residue blackened instantly and 
throughout when the strong acid was added to it, and 70 c.c. of 
the acid were required to bring about the desired pasty condition. 
After standing during 24 hours the mixture was poured into 
enough boiling water to reduce the acid to the strength of 3.5% 
and boiled over a free flame for 3 hours. ‘The filtrate from this 
treatment was added to that previously obtained, as above stated, 
after the first application of the strong acid, calcium carbonate 
was added to neutralize the acidity and the filtered liquid was 
evaporated to a syrupy condition. After decolorizing with bone- 
black, this solution showed quasi(a) D = 63°.42 and ‘* sugar” 
enough to amount to 9.65% of the dry wood. 
It is worthy of remark that in this trial where 50 grm. of 
wood were boiled directly in an acid of 3.5% and the residue 
was treated with sulphuric acid of 90% H,SO,, and where a 
3.5% acid was used again in the final hydrolysis, less sugar 
(14.385 + 9.65 = 24%) was obtained than had been got pre- 
viously where a smaller quantity of wood (10 grm.), a slightly 
weaker dilute acid (8%) and a more concentrated strong acid 
(92.5% H.SO,) were employed; for in that case the yield of 
“sugar” was 23.04-+ 5.64 -+ 23 = nearly 52%. So, too, in 
subsequent trials, less sugar was got from 50 grm. portions of 
wood after treatment with acid of 90% than had been got in the 
earlier trials. 
In respect to the action of strong sulphuric acid, it may here be 
said that (after the wood had soaked in strong acid) the 10 gram 
portions were boiled in 464 c.c. of acid of 3.5%, while the 
50 gram portions were boiled in 3250 c.c. of acid of 3%. 
Another difference of treatment in the two particular instances 
above cited was that the 10 gram portion had been leached first 
of all with ammonia, then boiled with dilute hydrochloric acid 
and afterwards soaked in strong hydrochloric acid, and again 
boiled in this acid, after dilution, before they were soaked in 
strong sulphuric acid; while neither ammonia nor hydrochloric 
