44 
district. The wound effect experiments and observations are based 
on the effects of re-opening old wounds by taking off a thin slice 
each day. However wound effect is not confined to cases where 
this method is adopted. 
Experiments made in the Singapore Gardens seem to show that 
what is known in Brazil as callingthe latex is really producing this 
wound effect though the incisions are not made in the same part of 
the tree. Indeed Mr. ARDEN notes himself that in some trees 
which had been previously tapped, a larger return was obtained 
from the other side of the tree than was obtained from a previously 
untapped tree. That the wound effect is diminished by allowing 
the trees to rest between the renewing of the incisions seems to be 
shown by some of the experiments, but further researches in this 
direction are required. 
Some experiments were made on the yield when leafless, when 
commencing to grow and when in full growth, showing an increase 
during the resting period, but more information is required on this 
point, as the author remarks, and in all experiments of this kind 
the condition of the weather at the time and for some time pre- 
viously should be taken. With respect to the tapping age, some 
quantity of rubber can be obtained as shewn in the report from 3! 
and 4 year old trees, but this is probably much too young to com- 
mence to work profitably and it is stated in some works that this 
young rubber is of inferior quality. It is probable that the size of 
the trees which varies a good deal according to position, soil, etc. 
is almost as important as age. 
As to the preparation of the rubber by acetic acid the samples 
turned out by Mr Arden left nothing to be desired in appearance 
and vvei*e highly valued by experts. 
The last section deals with the cost of opening and maintaining 
an estate, the figures seem approximately correct, though I should 
be inclined to consider the estimate for weeding too high, and atn 
much inclined to doubt the advantages of keeping the ground 
absolutely bare of low weeds at least, especially during the earlier 
years of the plant’s life before the ground is sufficiently shaded by 
the foliage to protect the roots from the sunheat. I he estimate of 
returns and value of the product is also very moderate, and is pro- 
bably much underestimated. 
The whole report is an excellent piece of work and worth the 
study of all those interested in Rubber. It is printed at the Tai- 
ping Government Printing Office. 
RUBBER TAPPING EXPERIMENTS IN THE 
BOTANIC GARDENS. 
In the month of February, we had a visit from M. BoNNECHAUX, 
a man of great experience in the rubber business of the Amazons, 
where he had spent some time among the Seringueiros, investigat- 
ing their methods and collecting notes and observations on all 
subjects connected with Para rubber. Having seen attempts made 
