Any sharp knife can be used to cut the bark, but it will pro- 
bably be necessary to supply the coolies with guarded knives 
which cannot be forced into the wood and so damage the tree. 
I have found a sharp chisel used with a hammer a good instru- 
ment for making the cuts. 
The common method in Para seems to be to chop at the bark 
with a small axe with a blade an inch in length, and to put a cup 
under each incision. But this is a cumbrous and wasteful me- 
thod and is not at all to be recommended. Another plan recom- 
mended by some is to make punctures in the tree and put cups 
to each puncture, hut the method above described has the advan- 
tage of collecting all the rubber into one cup, instead of having a 
lot of cups on the tree, saving time and labour. In South Ame- 
rica, cups of clay are prepared and stuck to the tree by means of 
lumps of wet clay, a very clumsy method, which also has this 
disadvantage, that the cups being quite open at the top, dirt and 
rain fall in and spoil the rubber. The best cups I have used are 
small cigarette tins with lids. These are nailed on to the base 
of the vertical cut with a small nail, hinge outermost. The lid 
is then pushed down so as to admit the rubber only. Any bits 
of stick, moss or dirt and rain will fall on the lid and not into the 
cup. 
The cuts having been made and the cups fixed in the evening, 
the rubber continues for some time to run into the cup, and in 
the morning is found to have partially or quite set, and in a few 
hours a solid cake of pure white rubber can be taken out of the 
cup. Little or no rubber flows during the day. 
There is usually a good deal of water which exudes from the 
rubber as it sets and after for a few days. This should be dried 
off in the sun, or the rubber can be pressed to get it out. The 
rubber shortly after it sets has a very foul smell, which soon goes 
off. In a few days the rubber becomes yellow, then dark grey. 
In Para it sCems that the rubber does not set without being 
smoked in the smoke of burnt nuts. The milk is taken up on a 
' bat let, and turned over and over in the smoke till it is dry, and 
then peeled off. This does not seem at all necessary here, unless 
it were necessary for improving the keeping power of the rubber. 
A sample cake of rubber prepared in the Botanic Gardens in 
1893, on being cut across in 1897, was found to be perfectly 
sound and elastic and the interior even retained the white colour 
of the fresh rubber. This had been simply prepared in the above 
mentioned way without the addition of smoking or any other 
process. 
Trees, if carefully cut, recover from their wounds very soon, 
and in a year or two can be cut again in the same place. 
Amount of rubber produced by a tree . — The exact amount of rub- 
ber which can safely be drawn from a tree is not yet settled ex- 
perimentally, but two pounds may be safely reckoned on for a 
year’s tapping of a five or six years old tree if well grown, and it 
is probable that a larger 'quantity than this can be taken without 
harm. Of course much depends on the size' of the tree, which 
