Bark of the White Birch, 283 
generally be found in a state of decay while the bark, which covers 
them, is entirely sound. The bark may easily be collected in cylin- 
drical pieces, by shaking out its rotten contents. These cylinders 
are frequently converted into baskets and other articles, and very 
often employed for kindling materials, and for torches, in the noctur- 
nal excursions of youthful anglers. Recollecting these facts, 1 was 
induced to undertake afew experiments, with a view of ascertaining 
to what principle the bark owes its inflammability, and its power to 
resist the ordinary agents of decay. 
_ A portion of the hail; chipped fine, was acted upon by boiling 
‘water. The water separated neither volatile oil nor wax. It con- 
tained some extractive matter and tannin. Upon the same portion 
of bark, highly rectified alcohol was kept in gentle ebullition a long 
lime. The alcohol was decanted off and suffered to cool, ang age? 
was evaporated, a granular substance was obtained, which Be 3 ed, 
‘in appearance, the lighter varieties of muscovado sugar, or more 
closely, the sugar from starch. This substance possessed the follow- 
Ing properties : It was extremely combustible, and when thrown upon 
hot coals, it diffused throughout the apartment, a peculiar and very 
agreeable odor. It fused at a temperature of 454°.* After fusion, 
itresembled the darker-varieties of the resin from pine. By friction 
it exhibited negative electricity. It was insoluble in water, but. it 
teadily-dissolved in alcohol and ether. With several of the essential 
oils it combined, but with much greater difficulty than common resin. 
With the oil of turpentine, however, it very readily formed a clear 
solution.. It combined with solution of potassa, and from this alka- 
line solvent it was separated by the addition of an acid. 
These characters entitle this substance to a rank among the resins, 
and at the same time, they are sufficiently distinctive of a peculiar 
variety. The high temperature at which it fuses, and the odor afford- 
ed when thrown upon hot coals, are characteristic of no similar body. 
The bark, when acted upon by repeated portions of boiling alcohol, 
becomes no more combustible than ordinary woody fibre, and as_all 
nz,’ ae Pe ssras of the birch resin was put into a glass tube, and a like quan- 
tity of common: resin in another. The tubes, — with a thermometer, were 
resins 7 a to melt was noted. Common resin, under these circumstances, melted 
, 218° Far : 
