MANGROVE. 191 



strongly in favour of this new article in the prepara- 

 tion of leather. Shoes made of it were found much 

 more durable than those for which common leather 

 was used, while those parts of the skin most difficult 

 to be worked by the ordinary tan becomes by the 

 use of this as strong and elastic as the other parts. 

 When cut, damp does no injury to this substance, 

 whereas oak bark loses ten per cent, of its value by 

 being wetted. 



There is at present every prospect that the use of 

 the extract of bark will at length be adopted, and 

 that this substance will form an important article of 

 commerce between this country and Australia. In 

 the year 1823 the extract of the bark of two species 

 of mimosa, which are cut down for the purpose of 

 clearing the land, was imported from Australia, and 

 was sold to some English tanners at .50 per ton, 

 under the name of extract of wattle bark. It was 

 found on trial to produce as much leather as between 

 four or five times its weight of oak bark of fair aver- 

 age quality. It is not quite equal in strength to the 

 extract of oak bark, but the importation price more 

 than counterbalances this inferiority, and this will be 

 the case, notwithstanding the distance of New South 

 Wales, as long as mimosa-trees are cut down in 

 clearing land for cultivation. 



The bark was stripped from the trees in August, 

 September, or October. The rough outward bark 

 was taken off, and the inner bark while green 

 crushed in a mill with fluted copper rollers like a 

 sugar-mill. It was then put in a copper boiler con- 

 taining clear water, 100 Ibs. to 100 gallons, and 

 boiled gently during two hours ; the decoction was 

 then strained through a sieve into broad flat copper 

 pans, and evaporated to the desired consistence. 

 One ton of bark produced 400 cwt of extract when 

 brought to the consistence of tar. If made hard as 



