142 CHEMICAL INDUSTRY IN KWANGTUXG PROVINCE 



affected by acids and alkalies. It is also used as Chinese 

 red ink and as a medicine. 



Red Lead. — Lead is also made in Wing Kat in Canton. 

 It is made by the direct oxidation of metallic lead. The 

 process is carried on in two stages. In the first operation, 

 the lead is converted into lead monoxide by heating with 

 free access of air in a large iron pan which can hold 1,000 

 catties, to a temperature just above that of melted lead 

 (840 deg. C). The temperature must be carefully regulated, 

 for if the lead monoxide melts, it passes into ordinary 

 litharge, from which red lead cannot be made. In order to 

 do this, it has to be stirred frequently. Finally the un- 

 oxidized lead is allowed to run off, and the lead monoxide is 

 taken out and cooled. It is pale yellow, of granular texture, 

 and contains pellets of unoxidized lead. It is then immersed 

 in water to separate the impurities and dirt from it, then it 

 is taken out of the water, dried and finely ground and then 

 transferred to the second process. 



In the second process, it, is heated to a dull red heat in 

 a larger pan. The mass is stirred frequently to assist the 

 absorption of oxygen, and to develop the color. It takes 

 several days to complete the process, and then the furnace 

 is allowed to cool. The product is ground and then sold as 

 a pigment and is also used for glass making. 



Soap. — The methods employed by the people in this 

 province for making soap are very crude. The art of soap 

 making is very old; only Chinese soap was used before 

 foreign soaps were introduced into Kwangtung. 



Instead of treating lard or fatty material with a solution 

 of sodium hydroxide or potassium hydroxide, lime is used to 

 react with the oil. So instead of soda soap and potash soap, 

 we have lime soap which is made in the shape of a bowl and 

 is termed "bowl soap." It is hardly soluble in water, and 

 is used only for washing purposes. 



Fire crackers and fireworks are made in Fa-Ti j£ i$, 

 Tung Koon M % and Im Bo f| p. Nitre which is the chief 

 constituent of these minor explosives has been known in 

 this country for many centuries. 



I have given you a brief outline of the chemical industry 

 of Kwangtung province. You see that owing to the lack of 

 machinery everything is done by hand-work, and. owing to the 

 lack of scientific knowledge, there is little improvement in 

 methods and products. Furthermore, things are made on a 

 small scale as hand-power and, foot-power cannot compete 

 with machinery; so there are no facilities for handling large 

 quantities on an industrial scale. As much time and energy 

 are wasted the manufacturers do not get much profit by the 

 industry. 



