Ill 
sphere of vegetable life, a brief exposure to the direct rays of the 
sun destroys its green color completely* 
Professor Vogel conjectures that the formation of tannin in the 
living plant is to some extent influenced by light. This supposition 
is supported by the fact that the proportion of tannin in beech or 
larch bark increases from below upward — that is, from the less illu- 
minated to the more illuminated parts, and this in the proportions of 
4:6 and 5:10. 
Sunny mountain slopes of a medium height yield, according to 
wide experience, on an average the pine-barks richest in tannin. In 
woods in level districts the proportion of tannin is greatest in local- 
ities exposed to the lieht, while darkness seems to have an unfavor- 
able effect. Here, also, we must refer to the observation that leaves 
exceptionally exposed to the light are relatively rich in tannin. 
We may here add that in the very frequent cases where a leaf is 
shadowed by another in very close proximity, or where a portion of 
a leaf has been folded over by some insect, the portion thus shaded 
retains a pale green color, while adjacent leaves, or other portions of 
the same leaf, assume their yellow, red, or brown autumnal tints. If, 
as seems highly probable, these tints are due to transformation pro- 
ducts of tannin, we may not unnaturally conclude that they will be 
absent where tannin has not been generated. — Jour, of Science. 
Box%vood^ which is almost exclusively used for wood engraving, is 
becoming more and more scarce. The largest wood comes from the 
countries bordering on the Black Sea. The quantity exported from 
Poti direct to England is immense; besides this, from 5,000 to 7,000 
tons of the finest quality, brought from Southern Russia, annually 
pass through Constantinople. An inferior and smaller kind of wood, 
supplied from the neighborhood of Samsoun, is also shipped at Con- 
stantinople to the extent of about 1,500 tons annually. With regard to 
the boxwood forests of Turkey, the British consul at Constantinople 
reports that they are nearly exhausted, and that very little really good 
wood can be obtained from them. In Russia, however, where some 
little government care has been bestowed upon forestry, a consider- 
able quantity of choice wood still exists; bui even there it can only 
be obtained at an ever-increasing cost, as the forests near the sea 
have been denuded of their best trees. The trade is now entirely in 
English hands, although formerly Greek merchants exclusively ex- 
ported the wood. In the province of Trebizonde the wood is gen- 
erally of an inferior quality; nevertheless, from 25,000 to 30,000 cwt. 
are annually shipped, chiefly to the United Kingdom. 
Seeds of /^<f^^x —The botanist of the Ohio Agricultural Station 
has been counting and estimating the number of seeds found upon a 
single plant of the most obnoxious w^eeds grown in that State. In the 
shepherd's purse he found the number of seeds in a medium-sized 
plant, 37,500; in the dandelion, 12,100; wild pepper-grass, 18,400; 
wheat-thief {Lithospermum arvense), 7^000; the common thistle (O/-- 
sium lanceolattuii), 65,366; ' camomile, 15,920; butter-weed, 8,587; 
rag-weed, 4,366; common purslane, 388,800; common plantam, 
42,200; burdock, 38,860. . . , 
Procuri7io Fire with the Bamboo.— In the new edition of Mason s * 
