NOTE ON BABUL. 11 



(d) BARK. 



Babul bark is used to some extent as a dye, and, according to Dyes 

 and Tans of Bengal by H. McCann, the following is a recipe for dyeing 

 cloth a dark brown colour : 



" For dyeing a yard of cloth, a pound of the bark is cut or broken 

 into very small chips, and is boiled in about 5 Ibs. of water until about 

 3 Ibs. of water remains. The solution is then allowed to cool. A pice 

 weight of alum (about -g- oz.) is then pounded and mixed with the solu- 

 tion. The cloth to be dyed is washed in pure water, and the moisture 

 well wrung out of it. It is then steeped in the above solution, and is 

 afterwards put to dry in the shade. This steeping and drying is re- 

 peated two or three times." 



It is, however, chiefly as a tanning agent that the bark of Acacia 

 arabica is of value. 



Properties. 



Although Babul bark is a good tan bark, it is stated that it can only 

 be used alone for certain purposes, such as for the soles of boots, for 

 it is a " harsh " bark, that is, it produces brittle leather. If, however, 

 the bark of Cassia auriculata is added to the Babul bark this brittle- 

 ness is overcome. 



The following figures, from the analysis made by an English firm 

 on raw hides sent home, are of interest as showing, in the case of Babul 

 and other well-known tan bark trees, the amount of tannin matter 

 absorbed by a hide, or, in other words, the percentage of tannin in the 

 bark which can be utilized : 



Acacia arabica 



leucophloea 

 Shorea robusta 

 Cassia auriculata 

 Terminalia Chebula 



Trunk bark. Twig bark. 



Per cent. Per cent 



17-1 11-7 



15-6 5-8 



8-2 9-0 

 18-7 

 30-0 



Method of Tanning. 



Mr. Pethe, Extra- Assistant Conservator of Forests, Bombay, gives 

 an interesting account of the method of tanning adopted in Poona, 

 of which the following is the substance : 



The bark of the best, or " Godi," variety of Babul only is used for 

 tanning, and this bark is removed from the tree as soon as possible after 

 felling, and before it has had time to dry up. The only instrument 

 used for removing the bark is a wooden mallet which loosens it until 



