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RA RUBBER ELASTICA 
The seas milky exudation obtained from the 
k of various species of Hevea 
Fam. Euphorbiaceae purge Family 
Native of Brazil and cultivated. 
DESCRIPTIVE LABELS 
STARCH 
Starch is manufactured by most plants, as a reserve 
food supply, from the water taken in through the 
roots and the carbonic acid gas inhaled from the atmos- 
phere; the chemical combination is effected by the 
sun’s energy, directed by the green coloring matter 
(chlorophyll). Starch is mostly stored in the form 
each plant that they afford an excellent method of 
identifying the latter, even in powder. 
RUBBER 
Elastica, U. S. Pharmacopoeia 
Rubber, India rubber, or Elastica consists chiefly 
many plants, existing in special milk-tubes of the bark 
and wood. The bark is cut or punctured, when the 
milk exudes and is caught in some receptacle. It may 
also be obtained by grinding up the bark, leaves and 
other parts and extracting with petroleum, bisulphide 
of carbon or other solvent. The milk is coagulated 
by various methods, mostly by subjecting it to the 
action of smoke, and the coagulated mass, often 
losing water by slow evaporation, takes on the dark 
color, toughness and elasticity characteristic of rubber. 
er is more valuable in proportion as its percent- 
age of caoutchouc is greater, and that of its resin less. 
It is proposed during the coming year to largely extend 
this feature of our labeling. 
