464 
work'; and to this end I have had made in Manchester, by a firm 
of manufacturers of rubber machinery, at the expense of the 
Colonial Government, machines for practically working up and 
vulcanising rubber, and I intend with the aid of these machines 
to manufacture test pieces of vulcanised rubber from raw rubber 
taken from trees grown in various localities of different age and 
cured in different ways. With these samples of vulcanised rubber 
physical tests of elasticity and tensile strength will be carried out, 
and a just comparison of the samples among themselves, and with 
true South American Para, can be made. There are special diffi- 
culties in carrying out physical tests on india-rubber, and there is 
at present no uniform method of stating results ; comparisons 
between tests made by different places are therefore of little value, 
and it is essential that all the work be done in the same manner on 
the same type of apparatus, to eliminate the personal equation and 
correctly ascribe to each variant factor in the production of the 
raw rubber its consequent variation in the quality of the product. 
When this is done I shall be able to say with certainty which 
method of preparation gives the best results, and to ascribe cor- 
rectly to each and every one of the variable conditions under which 
the rubber is produced its true influence on the quality of the 
rubber. This work I look upon as being important, and it will, 
I trust, settle decisively many of the problems which now are con- 
troversial. To see clearly the necessity for the work, and to have 
gained the insight into the methods of treating and vulcanising 
rubber necessary for carrying it out, are the direct results of my 
visit to England, and the time spent in the works of the rubber 
manufacturers there. 
PREPARATION OF RAW RUBBER. 
14. I have already stated I am not at present in a position to 
say decisively how the rubber should best be coagulated and pre- 
pared for export, but I am. inclined to recommend that as little as 
possible in the way of acids or drugs should be added to the milk 
or latex. Where a washing machine is used, the milk might, 
I think, with advantage be allowed to coagulate b simply standing 
for 24 or 36 hours and allowing the natural fermentation, or 
scouring, which takes place,, to produce coagulation. This of course 
will preclude any possible additions of preservative, such as 
formalin or dilute ammonia, to the latex in the cups and it will be 
desirable to keep the latek as concentrated as possible. This 
natural method is of course only possible where a washing machine 
is used, and it involves more time being taken in the actual coagu- 
lation process. There is among the manufacturers an objection to 
the use of any acid or addition of any drug at all to the rubber 
during coagulation, from fear that traces of it might be left in the 
rubber, even after washing. If there were an appreciable amount 
remaining, it is highly probable that it would give trouble during 
working and Vulcanisation of the rubber by acting chemically on 
some of the ingredients with which the rubber is mixed and perhaps 
producing gases which would form blow holes in the finished goods. 
