ECONOMIC POSSIBILITIES OF MANGROVE SAY AMPS. 



207 



of ciitcli without an_y complicated processes in this laboratorj'. Our eutch 

 is a dry, bro\ra solid "with a Ijrillant, almost metallic, fracture. It is 

 easily and completely soluble in water and the analysis shows the follow- 



ing constituents : 



Constituent. 



In parts per 100 of 

 water-Iree material. 



I. 



II. 



'. 



Per cent. 

 2.6 

 1.9 

 98.1 

 28.8 

 69.3 



Per cent. 

 5.7 

 1.3 

 98.7 

 26.1 

 72.6 



Insoluble _ - 



Soluble 



Non Tannin 







The following was the method used to prepare the cutcli: 



The finely ground bark was leached with cold water, and this sohition 

 evaporated to dryness in vacuo. Hot water extracts too much of the coloring 

 matter, and no more tannin than cold water. The evaporation, at least the 

 latter stages, must always be made in vacuo to avoid burning the cuteh. It is' 

 sufficiently obvious that the extraction on a large scale would be carried out in 

 such a manner that strong solutions would be employed to leach fresh bark 

 while weak ones would be used to extract the last percentages of the tannin from 

 the partly exhausted bark. All the parts of the factory, except the vacuum 

 dryers, could be built on the ground, and it is evident that the fuel for the 

 boilers and for the dryers would cost very little, so that it would appear that if 

 the cutch manufacture were taken up in connection with the lumbering or 

 firewood industry that it would be exceedingly profitable. 



Tables of analyses made on mangrove tan barks are given below. It; 

 will be noted that the Imrks from Mindanao run very much higher in' 

 tannin than those from Mindoro, and it has often been observed that, 

 as the equator is approached, the tannin percentage increases. The 

 analyses below were made by the methods of the International Leather 

 Chemists Association, using the American "shake modification." As 

 our machine does not give very violent shaking and as we have used 

 Tinchromed hide powder, it is possible that our results may be as much 

 as 2 per cent low. We are now taking measures to standardize our 

 analyses with those made by a recognized leather chemist and in a 

 subsequent communication will report several hundred analyses of man- 

 grove tan barks from the southern islands, so that perfectly reliable 

 data will be at hand for possible investors in this field. 



Botanical determinations of the mangrove barh samples: First lot,' 

 from Mindoro. Mr. Merrill of the Botanical Section of this Bureau made 

 the identifications. The botanical material was very poor and was not 

 preserved. 



