﻿PHILIPPINE FIBERS. 89 



contains the most widely known and important Filipino drug as a 

 by-product. The alkaloids from dita bark are being investigated by Dr. 

 E. F. Bacon of this Bureau. 9 



Only two soda digestions on dita wood were made. The wood is very 

 easily reduced, but its yields are 5 to 10 per cent lower than those of the 

 others under identical conditions of treatment. 



Experiment 1. — Strength of liquor, 4.4 per cent; 20 per cent caustic soda used 

 calculated on the air-dried weight of the wood; pressure, 5 to 6 atmospheres; 

 time, 8 hours; yield, 35 per cent. 



Experiment 2. — Strength of liquor, 3.3 per cent; 15 per cent caustic soda used 

 calculated on the weight of the wood; pressure, 5 to 6 atmospheres; time, 8 hours ; 

 yield, 38 per cent. 



SULPHITE WOOD PULP. 



I have conducted a large number of sulphite digestions on selected 

 species of Philippine woods, under varying conditions of strength of 

 liquor, duration of boiling, temperature and pressure. An upright, steel 

 digester capable of holding several pounds of raw material was con- 

 structed for these experiments. The conditions obtained in practice 

 were thus closely approximated and they furnish reliable data which can 

 readily be calculated in terms of ton lots of raw materials and of 

 chemicals. 



Considerable difficulty was encountered in constructing a gas-tight 

 digester and in protecting the iron shell from the corrosive action of 

 sulphite liquors. After failing in several attempts to make sheet-lead 

 or silicate-paint linings which would hold, the following arrangement 

 suggested by the Director was adopted throughout all the sulphite 

 experiments. 



A large stoneware chemical jar with ground stone cap and spring clip seal was 

 placed inside the steel digester shell and surrounded with water containing 

 sufficient alkaline bicarbonate to equalize the pressure produced by the free 

 sulphurous acid gas on the- inside of the jar. A drop tube carrying a thermometer 

 and dipping into the outside liquor between the stone and iron walls allowed of 

 perfect registration of the temperature conditions of the digestions. 



In a small way, we were able to deposit a very smooth adherent lead 

 lining on iron by the Bett's 10 process for refining base bullion in 

 fluosilicic acid solution, but the proper current density and other condi- 

 tions were not at hand for lining our large digester in this manner. 



The woods were barked and chipped in the usual manner and cooked 

 by the quick-cook system, namely at high temperatures for a relatively 

 short time. 



"This Journal (1906), 1, 1007. 



10 Electro Chem. and Metallurgical Ind. (1905) 3, 272. 



