d burn
fiercely because of the pitch they contain. This is true but the
chemists have added another reason. Pine gives off much hydrogen
when heated and this light and inflammable gas gives much flame.
Even in pine wood which does not seem resinous to the touch there
is much of this volatile inflammable material and a good store of
pine kindlings is a first requisite in every well ordered country
household. Of the hard woods hickory is easily king as a fire
holder. Yet the oaks, white and red, and the sugar and black
maples are not far behind in value. Our American white ash and elm
rank well up with the oaks, so does beech, while the softer woods
fall behind. Moreover, trees grown on high, droughty, barren soil
show greater heating power than those of the same variety which
happen to stand in rich, but moister soil.

Long ago an American chemist confirmed what the practical
experience of the woodman had already decided. Marcus Bull's table
of the heating value of American woods is as follows: Shagbark
hickory, 100; white oak, 81; red oak, 68; sugar maple, 60; red
maple, 54; white ash, 77; chestnut, 52; white beech, 65; black
birch, 63; white birch, 48; pitch pine, 43; white pine, 42.

Wood, according to the chemists, is a carbohydrate and the greater
the proportion of carbon which it contains the greater is its
heat-giving value, the greater the proportion of hydrogen the
greater the output of ruddy flames. Yet chemists, who are so sure
the alchemists had no ground for their beliefs, do not always
agree among themselves. Professor Bull's table of the heat-giving
properties of the various woods has been declared inaccurate by
other chemists, in spite of the fact that experience in actual use
bears it out in many particulars. Again, either the chemists of
Europe are at variance with ours or else their trees are, for
Gottlieb's table of the heat-giving properties of European trees
of similar varieties turns ours upside down. Gottlieb's table of
calorics puts oak at the bottom of the list and pine at the top.
It is as follows: Oak, 46.20; ash, 47.11; elm, 47.28; beech,
47.74; birch, 47.71; fir, 50-35; pine, 50.85.

There is a certain interest in all this, but to him who lights the
Yule log on Christmas Eve it probably matters little. He knows
that pine will kindle his fire readily and that one of the hard
woods will hold it longest. He knows that out of the leaping
flames, whether they be composed of phlogiston or inc