ON THE PRODUCTION OF FURFUROL. 339 
plan and to operate upon bran thus exhausted by either 
method, and afterwards dried in the sun, or otherwise. 
When mixed with the acid, the exhausted bran does not 
become pasty and adhesive, as happens with bran in its or- 
dinary state ; the mixture is thus more quickly and easily 
made and handled. 
Other vegetable tissues besides bran yield furfurol when 
thus treated, as beech-sawduat, of which 3 8 ounces, finely 
sifted, afforded not less than one ounce of the oil., very pure 
and free from pungency. From these experiments I am in- 
clined to hazard the conjecture that the substance which 
yields furfurol may possibly be the matiere incrustante of 
M. Payen, which forms an important constituent of ordinary 
woody tissue. The bran, after exhaustion by potash, or by 
the lactic acid developed by fermentation, and well washed, is 
reduced to a mere membrane, which, under the microscope, 
exhibits a curious dark tesselated or spotted appearance, 
as if incrusted with regular and uniform patches of brown- 
ish opaque matter. 
The following particulars may now be added to the de- 
scription formerly given of the properties of furfurol, some 
of which, from the small quantity then at my disposal, were 
open to correction. 
When just distilled, it is nearly colourless, but in a short 
time becomes yellow even in the dark, undergoing but little 
further change. Exposed to light it becomes brown in a 
few hours. In the hydrated state or in contact with water, 
this change of colour occurs much more slowly. Pure fur- 
furol at 60° Fahr. has the specific gravity of 1.1648. In a 
glass retort, containing some strips of copper foil, it boils 
regularly and uniformly at 325° to 326° Fahr., the baro- 
meter standing at 29.9 inches. Some blackening and slight 
decomposition take place with every distillation. It dis- 
solves in twelve parts of water at 60°, and is more soluble 
at higher temperatures, since a cold, milky, emulsion-like 
