145 
Composition of Latex. 
Water 
Acetone extract (resin,! ... 
Protein 
Ash 
Caoutchouc (by difference) 
Four year old. 
IQ year old, 
70.00 
60.00 
1.22 
I.65 
1.47 
2.03 
O.24 
0.70 
27.07 
35.62 
They then examined the aqueous extracts from the total solids 
of these latices in respect of their reducing action on Fehling’s 
solution and obtained the following results in terms of glucose. 
Before inversion. 
Latex from 10 year old trees none 
Four years old ... ... trace 
Leaf stalks ... ... 0.36 
These figures are interesting as pointing to the much larger per- 
centages of Carbohydrates contained in the latex from primary tissue. 
They aie only of relative value and do not show the actual amount of 
sugars in the original latices as these are partially destroyed by the 
evaporation of the latex to dryness. 
The appearance of the latex from the leaf stalks under the 
microscope is interesting and suggestive. A relatively small number 
of caoutchouc globules of the ordinary appearance are to be seen with 
a much larger number of smaller globules about one-third of their 
size. These small globules are in rapid Brownian movement and are 
not so well defined as the Caoutchouc globules having apparently a 
much lower refractive index. 
After inversion, 
0-34 
0.79 
2.25 
The latex from the petioles idiffers from that of the bark chiefly 
in the much higher content of the nitrogenous matter. There is also- 
nearly another 3 per cent, of resins or other matters soluble in acetone. 
The acetone extracted rubber from the latex of the petioles when 
allowed to stand for a few months is fairly tough and elastic and 
resembles rubber from mature trees similarly treated. — Ed. 
JViETBYL-INOSITE IN RUBBER. 
A paper on this substance was read lately at the Chemical 
Society (March 2) by Dr. Pickles, who had isolated it from smoked 
Para Rubber prepared at Singapore and from fine Hard Para of com- 
merce. It is one of the sugars of latex and had previously been 
found in latex collected in Java De Jong. It does not occur in 
biscuit and crepe being soluble and washed out in preparation. The 
smoked rubber referred to was doubtless the rubber prepared from 
the latex at the Botanic Gardens. Dr. Pickles suggested as a 
possibility that methylinosite is the precursor of rubber in Hevea 
Braziliensis and outlined a scheme for the gradual transformation of 
methylinosite into Para rubber by oxidizing and reducing enzymes 
assumed to be present in latex (Chemist and Druggist 1911, p. 1 14 
extr). 
