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On 30th November 1 tapped two trees of the respective circum- 
ference of 63 and 60 inches, obtaining therefrom 6 lbs. oz. of 
rubber. As to the age of these trees I can say nothing, as they are 
wild frees growing on the property. On 3rd December I tapped a 
rubber tree planted by myself, age 4 years 4 months, girth 26 
inches, height 27 feet, the result being oz. of rubber. Eight 
days afterwards I again tapped the tree and obtained f of an ounce 
of rubber, making total product 3J ounces. A few days later 1 
tapped ten trees, age 4 years and 4 months, average girth 23 inches, 
obtaining therefrom 22 ounces of rubber. These trees could all 
have been bled again, the second operation in no way affecting the 
tree, as I have proved by the first named experiment. In both 
cases, the quality ' of the rubber after preparation was excellent. 
On 7th December, I tapped a tree of the age of 3 years and 
4 months : result f oz. of rubber of poor quality, sticky and little 
life in it. It need hardly be remarked that these experiments were 
made not for marketable purposes, but in order to see what the 
increase in yield might be in each successive year. 
In order to compare these figures with others, I will quote those 
obtained by the writer of the article previously referred to. Mr. 
Weber gives the following as the results of his experiments made 
at the plantation of Las Cascadas on the Isthmus of Panama : — 
Per Tree. 
Five-year old' trees, mean yield of 77 trees ... ... 2*3 oz. 
Six-year ,, ,, ,, 61 „ ... ... 2-0 ,, 
Eight-year „ ,, ,, 61 ,, ... ... 1*8 
Twelve-year ,, ,, 61 „ ... ... 4’3 ,, 
Mr. Weber states, and in this I quite agree, that the tree can 
with perfect safety be tapped twice yearly ; thus the annual rubber 
yield may be taken at double that in the last column of the table. 
He further observes that he considers his figures as rather below 
than above the mark. It will be remembered that Mr. Weber 
gives the amount of rubber contained in the latex at from 26 to 3 1 
per cent. This is far lower than I have ever obtained. According 
to Dr. U re and Professor Faraday, the percentage of pure rubber 
in the latex is 45 per -cent. I have never found the milk of the 
Castilloa give less than 39 per cent., and in one case, with unusually 
thick milk from an old much tapped tree, I obtained as high as 
49 per cent. If, then, we take the yield of a 6-year old tree at 1 lb. 
13 ounces, as given by Mr. Weber, the result would be at 40 per 
cent., say ii|- oz. of rubber, which is, I think, a perfectly safe and 
conservative estimate. I have no doubt, as Mr. Weber states, 
that trees can with perfect safety be tapped twice a year, and 
though the yield may not be doubled, a very material increase of 
production will result. 
My experiments have shown me that trees that have already 
been bled yield their latex much more freely than those bled for the 
first time. This war. most noticeable in operating on a number of 
trees in my own land, when I found that the milk flowed more 
readily and copiously from those that had been apparently maltreated 
for years than from splendid trunks which did not bear a scar. It is 
