26? 
Mr Kent on the Ext?' act of Mimosa Ba?'k, 
From evidence before the Committee, appointed to investi- 
gate the subject, it appears, not only that all the oak bark of 
this country is purchased by the tanners, but that importations 
of foreign bark take place to the amount of about 10,000 tons 
annually. Of the whole quantity of bark employed in London 
and its immediate vicinity, nearly four-fifths are foreign bark, 
imported from the opposite coast of France and Flanders, and 
purchased at the price of about L. 14 per ton. 
The quality of leather is estimated, in a considerable degree, 
from its colour ; the paler this is, the better price it brings. The 
bark of the alder and larch is capable of converting skin into 
excellent leather, but on account of the reddish-brown colour of 
such leather, it is very difficult of sale. A similar objection ap- 
plies, in a greater or less degree, to leather prepared either of 
oak-bark, or of mimosa-bark. But the importance of the cha- 
racter in question has not been found to be established upon fact ; 
and there is reason to think that the prejudice arising from it 
may in time be overcome. 
From experiments made with the mimosa extract, it appears 
that a given weight of it will produce as much leather, as from 
four to five times its weight of oak-bark. It is therefore some- 
what inferior in strength to the extract of oak-bark. But the 
inferiority of price of the mimosa extract, more than counterba- 
lances its comparative deficiency in this respect ; for, notwith- 
standing the cost of freight from so distant a country as New 
South Wales, the expence must on the whole remain very mo- 
derate, so long as the mimosa trees continue to be cut down, for 
the purpose of clearing ground for cultivation. 
Art. VII . — Report on the Present State of the Wooden Bridge 
at Montrose , and the practicability of Erecting a Suspended 
Bridge of I ro?i in its stead , By George Buchanan, Esq. 
Civil Engineer, and Lecturer on Mechanics at the School of 
Arts, Edinburgh. (Concluded from p. 156.) 
Having thus completed the formation of the chain- work, the 
next object is the construction of the roadway, and the suspend- 
ing of it from those main chains. This roadway I propose to 
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