At what 
interval the 
incisions 
should be 
renewed, 
Collection of 
the latex. 
Coagulation. 
Yield. 
the incisions was not decided, as in some cases the tree continued 
to exude latex even after having been tapped on thirty consecutive 
days. In a few cases the maximum yield was attained on the 
eighth day; while, in others, there was a gradual increase up till 
the fourteenth tapping. This difference in the behaviour of trees 
makes it impossible to lay down any hard and fast rule as to 
the number of times it is advisable to renew the incision, but in 
the majority of cases the maximum yield will probably be reached 
at the tenth or eleven th renewal. 
9. Nor does it appear that there is anything to be gained by 
allowing the trees to rest a few days before renewing the incision, 
for the yield of those trees on which the incisions were renewed 
daily was equal to, and in some cases exceeded, that of trees which 
were tapped at weekly intervals. The ultimate result, therefore, 
would seen to be dependent, to some extent, upon the number of 
times the incisions are renewed, and it is doubtful if a saving of 
labour can be effected by renewing the incisions at long intervals. 
• 10. Ordinary cigarette tins were used for the collection of the 
latex. These were attached to the tree by a small nail driven 
through a whole in the side of the tin, a little day being placed 
between the tin and the tree to prevent any latex trickling down 
behind. 1 have had some similarly shaped tins made with a ‘dip " 
which is filed at the edges. The lip is simply pressed into the 
bark, no nail being required, while any escap: of latex is impossible. 
A loose lid prevents any dirt or pieces of bark from failing into the 
latex. The latex exudes very slowly, and it was generally found 
necessary to leave the tin on the tree for about an hour after mak- 
ing the incision. 
11. Several methods of preparing commercial “ india-rubber ” 
from the latex were tried, and coagulation by the addition of mer- 
curic chloride, sodium chloride, alum, acetic acid and other reagents 
was effected, but as these are still under consideration I do not 
intend to dwell upon them here. I am satisfied, however, that a 
good marketable rubber can be obtained, at a very small cost to 
the producer, in three or four days, if he has suitable drying 
accommodation at his command. 
12. The difference in yield of trees of the same age and growing 
under similar conditions is very remarkable, making experimental 
work difficult, especially when the number of trees at our command 
are limited. The amount of dry rubber obtained from 9-vear-old 
trees varied from 7 to 8l|- ozs. The average yield per tree was 
just under 2 lbs.; but, had all the trees been tapped on the most 
approved style and the incisions renewed an equal number of 
times, this amount would doubtless have been exceeded. 
13. The youngest trees tapped were 6 to 7 years old, and gave 
an average return of 12^ ozs. of dry rubber. This was the result 
of fourteen days’ tapping — /. a., the incisions were renewed on four- 
teen consecutive days, so that the average yield per day was less 
than 1 oz. of drv rubber. As pointed out at the commencement of 
