TWELFTH ANNUAL REPORT 3]^ 



by the natives in the treatment of diseases. Some of these 

 plants have important properties that are thoroughly understood, 

 and a feM'^ are recognized as the sources of various medicines in 

 the standard pharmacopoeia. A still larger number remain to 

 be investigated, in order to prove or disprove their reputed me- 

 dicinal qualities. The active constituents of many medicinal 

 plants growing in the Islands have been isolated and identified. 

 Dita, Datura, sihucao, macabtihay, hoyidiic, purging oils, and the 

 fish and arrow poisons may be mentioned as illustrating our 

 work along this line. 



46. Tans and dyes. — The assessed value of tanning materials 

 imported into the United States in 1910 exceeded $6,500,000, and 

 European tanners each year are becoming more dependent upon 

 imported materials. Data collected by the Bureau of Science 

 show that Philippine mangrove barks of the better species con- 

 tain about 30 per cent of tannin and indicate that a net profit 

 of from F50 to ?60 per ton can be made on tanning materials 

 derived from the mangrove swamps of the Philippine Islands. 

 There are areas of workable swamps in the Islands capable of 

 producing 1,500 metric tons of extract yearly, having a value 

 of ^210,000. The exploitation of these swamps would involve 

 a firewood and piling industry of about an equal magnitude. 



Many local species of plants yield dyes. These vegetable 

 dyes are of comparatively little importance commercially, as 

 most of them have been replaced by aniline dyes. 



47. Pape?- pulp. — This Bureau has carried on for several years 

 investigations of bamboo, cogon, abaca or hemp, and various 

 palm fibers as materials suitable for the commercial manufacture 

 of paper. The data collected have been accurately interpreted 

 with due regard to the local conditions bearing upon the subject, 

 and show that an industry of great potential economic value 

 can be developed. Careful surveys of some of the bamboo fields 

 available have been made. Sufficient data with regard to the cost 

 of the raw material, the quantity of bamboo available, the cost 

 of manufacture of the pulp, etc., are given to show that the 

 bamboo soda pulp can be developed into a profitable export trade 

 in direct competition with chemical wood pulp at present quo- 

 tations. Other countries have appreciated the work done by 

 the Bureau of Science, and our work will undoubtedly be the 

 means of starting the paper industry in the Philippines at some 

 future time. 



48. Coconuts. — The solution of the many problems relating 

 to coconuts, copra, and coconut oil is of vital importance to the 

 progress and success of this industry. The production and value 



