948 BULLETIN OF THE BUSSEY INSTITUTION. 
hornbeam, alder beech, pine, spruce, and birch), taken altogether, and 
with the bark that belongs to each part, is for the 
Stems of very young trees . . . . . . 1.23% of the dry wood 
Split wood from older trees. . . . . . 1.384% ,, < 
Branches not large enough to need splitting. 1.54% ,, - 
Fazots .0. jes 08 «ee ee SeawiGh ae # 
It would seem, however, that the woods burnt by Chevandier had been 
very sharply dried before weighing, and that the percentage of ashes 
above given must consequently be a trifle higher than would have been 
found by the usual method of estimation. No mention of the tempera- 
ture at which the woods were dried is made in the article from which the 
foregoing figures were taken. But in several other memoirs published 
by Chevandier, he distinctly states his habit of experimenting upon 
woods that have been dried at 140°(C.) [== 284° F.]. 
I have purposely omitted to mention in the table a large number of 
determinations of the percentage amounts of ashes in the charcoal of 
various kinds of woods that have been made by Violette,* Berthier,t and 
Karsten.{ Since the amounts of wood from which these charcoals were 
produced have been reported in most instances, it would at first sight 
seem to be an easy matter to calculate from the analytical data the percen- 
tages of ash in the original woods. Indeed, a number of results thus 
obtained by Berthier have been often cited in chemical literature. But 
the figures computed in this way often differ considerably from those 
that have been obtained by the direct incineration of wood, and there 
are grounds for believing that they are less trustworthy than the latter 
on the whole. 
One reason why the determinations made upon charcoal need not be 
quoted in this connection, depends upon the fact that most of them refer 
not to ordinary wood that has been burned with the bark natural to it, 
like wood that is used as fuel, but to wood that has been carefully 
deprived of its bark, asin the preparation of charcoal for the powder- 
maker. All of .Violette’s experiments, some of those of Berthier, and 
perhaps Karsten’s also, were made upon the charcoal of wood from 
which the bark had been removed, while most of the results given in the 
table undoubtedly refer to ordinary fire-wood that was burnt with its 
bark. 
It would of course be interesting, from the scientific point of view, to 
know how much ashes is yielded by barkless woods of various kinds; and 
it is undoubtedly true that more information upon this point may be got 
from the researches of Violette, and the other investigators of charcoal, 
than from any other source. But it does not appear that this informa- 
* “Annales de Chimie et de Physique,” 1851, 32. 341, and 1853, 39. 294. 
+ “ Traité des Essais par la Voie séche,” Paris, 1834, 1. 249, 260. 
t Cited in Schubarth’s ‘‘ Handbuch der technischen Chemie,” Berlin, 1839, 
1. 291. 
