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iPRAXINUS ORNUS. 
finger, and when applied to the tongue has a sweetish taste. 
Whether this may ever be accumulated in sufficient quantities to be 
collected as manna, we cannot pretend to say; * or whether the 
exudation of the manna, which is evidently distinct from the depo- 
sition we have noticed, is itself a diseased state of the plant, con-r 
sequent on the easterly wind, and, therefore, concurrent with the 
other appearance alluded to, and perhaps for this reason con- 
founded with it, is more than we can determine. If this clammy 
deposition was confined to vegetation, we might readily conceive that 
it was, in the first instance, exuded from the plants, and carried up 
by the heat of the sun in the form of a vapour, to be ugain depo- 
sited after the sun ha>l withdrawn its influence; but wood, cloth, 
paper, leather, and, in fact, every other substance which is exposed 
to the action of the atmosphere, presents a similar appearance. The 
like effecls, though in a much less degree, may frequently be seen to 
attend the east wind in our own climate. On the whole, the pro- 
duction of manna may be considered a subject worthy of further 
investigation, as leading to a better knowledge of vegetable phy- 
siology, a science which has not hitherto been sufficiently at- 
tended to. 
Dr. Fothergil! supposes the manna spoken of by the ancient Greels 
writers, to be portions of Olibanum, broken off in the conveyance, 
and still called manna of frankincense. 
Manna is a spontaneous exudation, which, when concreted into 
granules, is known in the market as " manna in the tear." To ob- 
tain it more copiously, incisions are made in the bark ; the best 
season for this process is a little before the dog-days commence, 
when the weather is dry and serene ; these incisions are first made in 
the lower part of the trunk, and extended upwards, at the distance 
of an inch, until they reach the branches, confining them to one side 
of the tree, the other side being reserved for the following year, when 
it undergoes the same treatment; these incisions are about a span in 
* Tlie manna of the wilderness, mentioned in tbe book of Exodus, lias been supposed 
by some authors to have been a deposition on the leaves of the trees, which fell off 
spontaneously : other authors consider it to have been the produce of insects. 
Major Macdonald Kinneir, in his Geographical Memoir of Persia, speaks of a sort 
of manna, which the Persians call Guz, that is supposed to be produced by small red 
insects, which swarm under the leaves of particular trees. According to Mr. Hunter, 
the Guz projects from the abdomen of the animal, in appearance like a tail, or bunch of 
feathers ; these animals are found on certain trees in Persia and Armenia, swarming in 
millions, and generating this substance until it gets long, and drops on the leaves, 
caking on tUem, and resembling beautiful bees wax. 
