386 
for any land except desert-like wastes similar to those in Mexico, 
outside of which it will probably never attain any importance. The 
rubber is not in laticiferous vessels, but in scattered cells, about two- 
thirds being in the bark. It is extracted not as liquid latex, but from 
chopped or ground-up pieces of the stem and branches of the shrub 
by mechanical or chemical treatment, the processes for which are all 
patents, more or less secret. 
The mechanical methods are cheapest, but the rubber contains 
more pieces of wood than when extracted chemically. Mostly 
Alkalies are used in the chemical processes, other chemicals are too 
dear in Mexico. The difficulty of extraction renders large Com- 
panies and plant a necessity. There are only fifteen Companies at 
present engaged in the entire industry, though the export was 
2,700,000 lbs. in the last six months of 1906 and 700,000 lbs. in 
January of this year. (Exports from Brazil from the year 1906 were 
15,774,840 lbs.) 
Older plants yield a higher percentage of rubber than younger 
ones, the plant cannot be profitably used until it is at least five years 
old. and as a rule ten years must elapse from time of sowing seed 
until the plant is ready for harvesting, but it appears that the new 
shoots which grow on the cut down stems may be collected after 
five years. Whether a third crop will follow cannot be stated with 
certainty. 
The chopped-up material gives from 7 to 10 per cent caoutchouc; 
the age of the tree and the dryness of the material effecting the 
percentage. There are a want of data concerning the composition 
of the rubber. The Director of a lqrge Company asserts that their 
rubber contains 20 per cent of resins ; it would appear that well- 
prepared stuff contains from 5 d to 70 per cent caoutchouc and 
from 12 to 20 per cent resins, with from 3 per cent upwards of 
water. 
Guayale rubber as put on the market contains considerable quanti- 
ty of woody fibre, which the methods of extraction have been 
unable to take away. This makes washing considerably difficult for 
manufacturers, and special machines have been designed for the 
purpose. This may account for its neglect by British manufacturers, 
though it has proved itself a middle-grade rubber, suited to many 
commercial applications and offering certain advantages in vulcanisa- 
tion. It is used mostly by American and German manufacturers, 
who have found it worthy of attention during the present high prices 
for Para. 
It does not appear on the lists of London Brokers, but the India 
Rubbe World quotes its price in New York on the 30th July last 
as 2 s. per lb., and the highest price of Para on the same date as 
£0-4-11, and fine Ceylon as £0-5-7. 
The Companies are mostly German, and the advent of an American 
combination in 1906, which attempted to gain complete control of 
the industry according to American Trust Methods, lowered the 
