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me that even with his imperfect mode of extracting the 

 tannin — the chips being coarse and his boiling apparatus 

 imperfect — he ' found the mesqtiite wood equal to the best 

 black jack bark, and superior to all others. When prop- 

 erly comminuted and extracted, the yield would be larger 

 than from the best bark. The sap of the mesquite, _ on ex- 

 posure to the air, becomes tannic acid. In splitting the 

 wood, frequently the tannin or tannic acid, will be met 

 with in circular crystals occupying small cavities in the 

 body of the timber. From experiments made by Dr. Park 

 in making an extract from the mesquite, he was satisfied 

 that the richness of the wood in tannin was such that, with 

 proper appliances, it would be a profitable business to 

 make catechu from it. The catechu of commerce is made 

 froin a tree of the same family with the mesquite, the acacia 

 catechu of India. 



With regard to the action of the mesquite tannin in strik- 

 ing through and through the hide, instead of beginning 

 on the external surfaces and gradually carrying the tanning 

 process into tlie interior, I learn that it is a process which 

 marks some other tanning materials. In a conversation 

 with Dr. Lyon, of San Antonio, an intelligent gentleman who 

 is engaged successfully in the tanning business in a small 

 way, he told me that the bean used in Mexico for tanning, 

 the name of which I have forgotten, and also some other 

 article — perhaps catechu — operated in the same way. It 

 is a highly important quality of a tanning material in the 

 southern country, as it pervades the whole body of the 

 hide with its antiseptic virtue and prevents decomposition. 

 The experiments made during the war in tanning with the 

 barks of the country during hot weather were attended 

 with great loss from the hides spoiling in the middle before 

 the tannin reached it. In cutting the hide, the external 

 surfaces are affected by the tannin, but the middle was 

 decomposed, and the hide .would split open. Dr. Park, to 

 show me the manner of the action of the tannin of the 

 mesquite, cut into the hide, and the section revealed plainly 

 that the process had^passed entirely through, affecting the 

 centre as well as the surface. It is not to be understood 

 that the whole body of the hide was perfectly tanned, but 

 that colored fibrous lines developed in a few days passed 

 from surface to surface, showing that the whole body of 

 the hid.e was penetrated by the agents and secured it against 

 all danger of. decomposition. Dr. Park lost no hides after 



