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bottle or biscuit, has formed upon the paddle, which is then 
removed and allowed to dry and season. By this method, 
not only is the rubber coagulated, but the creosote of the 
smoke acts as an antiseptic and prevents putrefaction of 
the albuminin the rubber. ‘The mass thus formed contains 
much water, which gradually dries out as the rubber is 
kept. As the process continues the color gradually changes 
from milky-white to yellow, brown, and black, the central 
portion long retaining its white color. By modern im- 
provements on the above method, the milk is coagulated 
by the addition of various substances and the water then 
squeezed out of it by pressure. Occasionally, the resins 
and other foreign matter are removed from the milk by 
chemical processes, leaving the rubber. Still other pro- 
cesses are described below. 
Rubber trees are now largely grown in plantations, 
especially in Java. 
THE SPURGE FAMILY (Euphorbiaceae) 
Nos. 844-906 illustrate Para rubber and articles made from it. This is the 
best quality of rubber known and is obtained from various species.of the genus 
Hevea. ‘These are large trees, native of the entire Amazon valley and extending 
somewhat into adjacent regions. 
844. Branch bearing leaves and fruits of Hevea brasiliensis Muell. Arg. Grown 
in Java and presented by William Fussani, 1919. 
845-847. Hevea seeds.—The seeds of a species of Hevea packed in charcoal, by 
a special process, the only way in which their vitality can be preserved 
for any considerable length of time. Presented by the India Rubber World. 
848.16 Rubber pick.—A pick used for puncturing the bark to cause the flow of the 
rubber milk. 
849. The same with a long handle. 
850. Another specimen of the same, presented by John Lane Beck, of New York 
City. 
851. The rubber milk as it comes from the tree. 
852. “White” rubber milk.—This milk, after remaining several years in a bottle, 
has naturally coagulated and formed itself into rubber. Acquired on the 
Upper Rio Negro by Weiss & Schmidt. 
853. ““Red” variety of same. Same source and donors. 
854. Tichella—Cups used for catching the milk as it flows from the tree. 
855. The same, presented by John Lane Beck. 
16 Unless otherwise specified, were presented by Nos. 848-871 Carlos Manuel 
Asensi, of the Rio Madeira, Brazil. 
