No. 133.] 4 CI* 



mined. This is a subject which ought to be investigated ; chem- 

 ists should turn their attention this way, because there is room 

 enough here to add a great deal to the wealth of the world. 



There is a great difference in the strength of hemlock bark. 

 That which grows in the region of the Catskill mountains is the 

 best that I have ever found. The oak bark of Delaware and 

 Maryland is considered the best of that kind. The hemlock of 

 Maine and New-Hampshire will not make as much leather, nor 

 as heavy leather, nor will the bark of Michigan or Ohio. Oak 

 bark is the best for tanning upper leather and thin .>ole leather, 

 while hemlock is the best, or quite as good for thick sole leather. 



The Buenos Ayres hides are thought to be the b^-st for sole 

 leather, yet they will not make as many pounds as the Oroaoco 

 hide. City-slaughtered hides are tanned principally in oak, and 

 they are used chiefly in the manufacture of harucsse.^, belt straps, 

 line boots and ladies' shoes. 



It may be a matter of curiosity and instruction to know how 

 long a tannery wiil last. This depends much ujx)n whether 

 steam is allowed to come in and keep the beams and timbers in a 

 moist state. The larger the timber is, the sooner it rots. A tan- 

 nery of a large and improved class will last from twenty to thirty 

 years, by having the beams renewed two or three times ; and this 

 is long enough, generally, to consume all the bark that from on^ 

 single neighborhood can be conveniently drawn to the tannerv. 

 When the tar.-vats are j^unk in clay, they are never known to 

 wear out , wlien they are filled in witli common earth, or even 

 tan, if the air can be excluded by having them kept wet on botii 

 sides, they will last almost any period. The old-fashioned heater 

 kind of leches will last about three years, and the timber around 

 them twic-e tliat time. 



There are three or fo:ir modes of h^atiiig, that have hitherto 

 been adopted. The late mode, by the pan, I have (bund to be the 

 cheapest and safest. Formerly, wood was used, but now, tan wet 

 from the leches, is in requisition; i; is good, and tlicapcr, and 

 will answer to make ste?m ard drive all neceE^aiy machinery. 



