BAMBOO-MANNA. 121 
we may actually find this earthy matter in the 
stems of trees, which, like straw, have a polished 
glassy outer surface—as the bamboo. Frequently 
indeed in the hollow trunks of this tree, the 
bamboo, large pieces of it are found, which are 
like the more friable sorts of stones in hardness, 
and are called by the name tabasheer. It is some- 
times called “* Bamboo manna,” and is still sold 
in Syria, Turkey, and parts of India as a medi- 
cine. 
Thus, to sum up what we have said about the 
proper food of the vegetable subject of our history, 
—the Tree—we find that it is obtained in several 
ways. The firm wood was got from the carbonic 
acid of the invisible air; the valuable nitrogen, 
which forms the parts of the seeds or fruit most 
nourishing to man, was derived from the am- 
monia floating in the air in small quantities; and 
its juices from the rain descending from the 
clouds. Besides these, the different saline and 
earthy matters, which we also find to form a part 
of the vegetable diet, were obtained from the 
soil, being received by the plant or tree by means 
of its roots. So that, wonderful to say, the plant 
receives by far the greatest part of the material 
