﻿100 RICHMOND. 



Bleaching powder (chloride of lime) is valued on its content of 

 available chlorine; it is somewhat unstable and it readily deteriorates in 

 strength on exposure to heat, air and moisture. When freshly prepared 

 it contains about 40 per cent of available chlorine. Analyses of several 

 samples of bleaching powder purchased in the Manila market have shown 

 a strength of less than 30 per cent in every instance. In view of this loss 

 which bleaching powder undergoes during long periods of transit, it is 

 questionable whether it would not be more economical to import the 

 liquid chlorine and manufacture bleaching powder here as needed. 



The older method of gas bleaching, making use of chlorine in the 

 gaseous form, was displaced by the use of chlorine in combination with 

 lime because of the simplicity and ease of control of the operation with 

 the latter, but with bleaching powder at $1.25 per hundredweight and 

 because of its arrival in Manila at a point nearer 20 than 30 per cent in 

 strength, it could not compete with liquid chlorine at its present market 

 quotations. 



About one-half of the world's output of bleaching powder is prepared 

 from chlorine made by electrolyzing crude salt. Crude salt from sea- 

 water evaporation is both cheap and plentiful. 



Mineral fillers. — Nearly all kinds of paper contain varying amounts 

 of some form of mineral matter. These are added to the pulp in the 

 beating engines for the purpose of increasing the weight, filling up the 

 pores and imparting a better feel and appearance to the finished sheet. 

 The substances best suited for these purposes are certain grades of 

 'clay, sulphate of calcium, talc, gypsum, barytes, etc. They should be 

 of light specific gravity, free from grit and should be white, showing a 

 low content of iron and organic impurities. 



The Mining Division of the Bureau of Science submits the following 

 data concerning the local supply of crude chemicals, their cost and 

 availability : 



Limestone. — The sources of supply of burned lime for Manila are 

 (a) the limestone quarries near Binangonan on Laguna de Bay in 

 Bizal Province and (&) a coral limestone from marine shells burned 

 near Malabon on Manila Bay. 



(a) The quarries at Binangonan have a present annual output of 

 about 600 tonSj mostly of water-slaked lime which is sold in Manila for 

 making mortar. This lime can be obtained fresh burned when it is 

 needed, as is the general custom throughout the Archipelago. The 

 product is a very fat lime, which swells when it is slaked to about three 

 times its original volume. The lime is valued at Binangonan in propor- 

 tion to its content of calcium oxide. The present prices are as follows : 



Quick lime, per cavan (about 80 pounds) 1*1.35 



Slaked lime, per cavan (about 80 pounds) 45 



The transportation charges from Binangonan to Manila are f*0.15 per 

 cavan, which make the prices in Manila "P1.50 and 1*0.60 per cavan for 



