£ 3 1 
and mammoth, lately found in Siberia, entire be- 
neath the frozen soil, in which they must probably 
have existed from the time of the deluge. I ex- 
amined a part of the skin of the mammoth sent to 
this country, on which there was some coarse hair j 
it had all the chemical characters of recently dried 
skin. 
Trees that grow in situations much exposed to 
winds have harder and firmer wood than such as 
are considerably sheltered. The dense sap is de- 
termined by the agitation of the smaller branches 
to the trunk and larger branches ; where the new 
alburnum formed is consequently thick and firm. 
Such trees abound in the crooked limbs fitted for 
forming knee- timber, which is necessary for join- 
ing the decks and the sides of ships. The gales 
in elevated situations gradually act, so as to give 
the tree the form best calculated to resist their 
effects. And the mountain-oak rises robust and 
sturdy ; fixed firmly in the soil, and able to oppose 
the full force of the tempest. 
The decay of the best varieties of fruit-bearing 
trees which have been distributed through the 
country by grafts, is a circumstance of great import- 
ance. There is no mode of preserving them ; and 
no resource, except that of raising new varieties 
by seeds. 
Where a species has been ameliorated by culture, 
the seeds it affords, other circumstances being si- 
milar, produce more vigorous and perfect plants ; 
and in this way the great improvements in the 
production of our fields and gardens seem to have 
been occasioned. 
q 4 
