The chemical composition of a latex has been stated by LAS- 
CKU.ES SCOTT to be as follows : — 
India Rubber ... ... 37- 13 per cent. 
Albumen ... ... 271 „ 
Resins 3 '44 >> 
Essential oils ... . ... Traces. 
Sugar .. ••• ■ 4' r 7 
Mineral matter ... ... * 2 3 ,, 
Water ... ... 5 2 ‘ 3 2 >> 
In the main this may be accepted as not far from the truth, but 
different latices shew variations in the amounts of the various con- 
stituents and the same tree will produce a latex of different pro- 
portional composition at different times and the proportios of the 
constituents will vary with the depth and nature of the incisions 
made iu the tree. 'Phis is only what would be expected when 
it is remembered that tissues other than the laticiferous are cut 
through during the process of tapping and the cells of each 
contribute their contents to make up the sum total of the mixture 
collected. Analyses shewing these variations are being made and 
will be published as soon as completed. 
The constituents of the latex may be arranged into two groups 
as follows: — 
(1) Rubber, Resins, Albuminous matter, Mineral matter. 
This «roup makes up the globules which can be 
microscopically observed in the latex and separated 
on filtration. 
(2) Water with Album enous matter, Sugar, and Mineral 
matter, in solution. 
This group constitutes the liquid separated in a pure state from 
the latex by filtration. To separate, in group r, the rubber from 
the other constituents appears at present to be a practical impossi- 
bility on a commercial scale : the task therefore left for the rubber 
grower is to separate group 1 from group 2 as perfectly as may be. 
If this were done the resulting substance would represent the 
purest and best possible rubber that could be prepared on the large 
scale from the latex, and as such it ought to command the best 
price As long however, as rubber is bought and sold by the 
appearance, smell, and strength, as they appeal to the rubber 
brokers, there is no guarantee that the best price will be given for 
the chemically pure product. 
I propose now to consider briefly the chemical characteristics of 
each of the constituents of the latex in turn, and then to discuss 
the processes that now are adopted for the coagulation and pre- 
paration of the rubber. 
India Rubber. 
Dealing first with the India Rubber itself. This substance in 
elementary composition is a compound of carbon and hydrogen 
and belongs to the class of bodies known as terpenes. It may be 
