^erve as a Substitute for Oak Bark. 14^ 



p"\Teumatlc oils, which it is rubbed with in the preparing 

 of it. 



• As to Cordovan and Morocco leather, they are made of 

 goats' skins, and prepared, the one with sumach, the other 

 with galls. 



We have said enough concerning the general principles 

 of tanning, so as to throw a light upon what relates to the 

 plants that can be made use of in it. 



There is abundance of these plants in our country, and 

 eight new methods of preparing leather with them have 

 been discovered. They have been treated of in a memoir 

 that was read before the academy on the 5th of last De- 

 cember. The author of this memoir, and the maker of 

 these new sorts of leather, is M. Klein, a native of Nauen. 

 Jle requested I should show him all the plants that I 

 thought lit for tanning. I have mentioned the names of 

 these plants to the academy, and specified their properties. 

 They are all indigenous plants, very common and abundant, 

 and which have been heretofore considered as noxious weeds, 

 as the utility of them v^as not known ; and accordinglv, 

 riieir being used in tanning will not be in the least hurtful 

 to private ceconomy. M. Klein has collected a considerable 

 quantity of these species of plants ; and among the eight 

 sorts of leather that have been made witli them there is very 

 fine Cordovan prepared without sumach, and tv/o sorts of 

 calf-skin, tanned only with leaves of trees. 



These coriaceous plants grow in >almost all deep places 

 and marshy grounds ; there are some of them found also 

 in sandy soil, on hills, and in woods. The hay which they 

 vicld is the coarsest of all, and in very small quantity ; the; 

 ■cattle never touch it, except when they are starving with 

 hunger. Such plants spoil good meadows. A great quan- 

 tity of them is to be had, particularly near laki-s and lararc 

 ponds ; and it is no exaggeration to say that tiicrc are si^^ty 

 fcpeeies of them. 



It is very easy to discover the chemical principles in 

 virtue of which these plants arg fit for tanning, if one ha* 

 a knowledge of those of sumach, galls, and ditrercut sorts 

 of bark. With regard to this point, the plants may be di- 

 vided into tv. o principal classes. The principles that are 

 cliieilv to be considered are found generally in all of themj 

 they are of A fixed, but still active, terreo-gimmty, or lerreo^ 

 TC'sinoso-gi/mmy nature. Besides these conmion principles, 

 >ome other very active ones exist in some of these plants, 

 ill a greiAicr or IcjS quantity; aJi'l this is v/hat conslitutc* 



the 



