THE ECONOMIC POSSIBILITIES OF THE MANGROVE 

 SWAMPS OF THE PHILIPPINES.' 



By EoBEET R. Williams. 

 (From the Laboratory of Organic Chemistry, Bm-eau of Science, Manila, P. I.) 



Tanning materials are being imported into the United States in such 

 rapidly increasing amounts that the importations now form a large per- 

 centage of the total quantity consumed. In ^ 1900 the assessed value of 

 such imports was about 1,600,000 dollars which in 1910 had gro^Ti 

 to a sum exceeding 6,500,000 dollars. The increase has largely been 

 due to the economical manufacture of extracts and to the development 

 of quick tanning processes which demand materials of high concentra- 

 tion. In 1909, the last year for which reliable figures are available,^ 

 10,779,177 dollars were paid for tanning extracts, while the total amount 

 expended by American tanners for vegetable tanning materials was 

 21,904,927 dollars. By far the most important extracts are South Amer- 

 ican quebracho and domestic chestnut. The cost of the former in 1909 

 was 5,877,989 dollars, and of the latter, 3,579,929 dollars. Hemlock, 

 palmetto, and gambler, supplemented in recent years by myrobalans and 

 mangrove, constitute the remainder of extracts used in tanning. 



Tanners in Europe also are becoming more and more dependent upon 

 imported materials. Eviropean importations include a larger proportion 

 of raw barks and woods, due to a slower development of extract tannage 

 on that continent. 



The extended use of mangrove bark, and more particularly mangrove 

 extract, is of comparatively recent development. The East African 

 swamps * have for a number of years furnished bark, chiefly for the Ger- 

 man market. Twelve thousand two hundred and sixty-three tons, to the 



' This paper is a continuation of the work begun by R. F. Bacon and Vicente 

 Q. Gana of this Bureau. See This Journal Sec. A (1909), 4, 205. 



" Commerce and Navigation of the United States. U. 8. Bur. Statistics 

 (1900-1910). 



'Tan bark and Tanning Extract in 1908. Bull. U. S. Bur. Census, Forest 

 Products (1911), No. 4, jVIarch. 



* Board of Trade Journ. (1905), Mar. 9, through Journ. She. Chem. Ind. (1905), 

 24, 298. 



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