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simpler methods, and it is only the incident of rain upsetting the 
normal state of tilings, and the varying rubber content of latex 
during the wintering months that call for a reading of the instru- 
ment. These methods are perhaps crude, but they are practical and 
suited to the intelligence of the factory cooly, and the results have 
been consistently good. Where tapping is done by coolies on daily 
wage entirely, bulking the whole of the estate’s latex is of course the 
surest method of ensuring standardization. 
Coagulation. 
Having bulked our latex and cup-waskiifgs the next step is to 
add the acid necessary for coagulation. This is done before the 
latex is put out into pans and a stock solution is kept ready in air- 
tight jars. The solution is made up of 12 oz. acetic acid and | lb. 
sodium bisulphite to one gallon of water-— one gallon of this being 
sufficient for 80 gallons of latex and cup washings. I have tried 
sulphuric acid on a small scale, but was not very successful with it, 
and did not continue experiments, the main reason being that we 
had buyers who relied on uniformity from the estate, and the 
change of acid might have upset previous vulcanization tests and lost 
the confidence of the buyers. Pans thoroughly washed are stacked 
at hand to receive the latex, each containing j of a gallon of 
water and one gallon of latex is poured into each pan with as little 
delay as possible after the solution has been thoroughly stirred 
into the bulk. Skimming is done at once with a strip of tin 
almost as broad as the pan and the pans are placed on shelves 
in cupboards screened all round by a drop-curtain of turkey-red 
cloth. The pans used are 16" x 10" x 4" and produce a dry 
sheet 25'' X 11" in the case of latex from old trees and one 
slightly smaller from young rubber. Coagulation is usually finished 
by 12.30 p.m. and this allows for latex being brought in carts from 
outlying fields two miles from the factory. The pans are left 
untouched overnight. The reason for the added water not being 
put into the bulked latex is that I found bubbles resulted from 
bad fusion of water and latex owing to insufficient stirring by coolies 
when not watched, sheets from the same jar or tank varying 
considerably. The method used leaves nothing to chance and is 
therefore preferable. There is also economy in the number of jars 
or tanks required for containing the bulk of latex before it is 
put out into pans. In tank coagulation the solution of acid is 
put into the latex after it has settled in the tanks aud before 
the partitions are placed in their slots. The majority of tanks 
I have seen do not give such good results as pans owing principally 
to the fact that the partition laths are not perfectly water tight and 
permit latex to ooze through from one division to another causing a 
ragged edge on each sheet which is difficult to get rid of. Most 
of them are also too big, without enough divisions to deal with 
the ever varying gallonage. When an estate has tapping done by 
