390 
occasion of the recent blow. The leaves, as was practically the case 
with all leaves throughout the storm area, were entirely stripped, but 
the branches, probably because of the stripping of the leaves and the 
main-stems, were very little broken. It is remarkable though I am 
not satisfied that any sequence of cause and effect is thereby indicated 
lhat almost the only rubber trees which were broken were certain 
trees at the Government Station at Nasitnu, which had been tapped 
at an early stage of their growth. This treatment resulted in an in- 
crease in the size of their heads as well as of these stems and possibly 
a correlative greater liability to damage from wind.” 
SYNTHETIC RUBBER. 
'Hie discoveries of Professor Harries, of Kiel in synthetic rubber, 
making turn out to be onlya new method of making it from isoprene- 
in which is polymerised on heating in a closed tube to above 100c with 
glacial acetic acid. The produce, it is noted, is “very expensive” and 
only of scientific interest at present, but if it could be produced 
CHEAPLY its purity is such that it would compete with natural 
rubber. “ It is rumoured that a company is to be formed with a 
capital of a million to start the manufacture.” (Ext. Chemist and 
Druggist, April 23, p. 121).— Ed. 
TOXINS. 
In the annual report of the Board of Scientific Advice for India 
from 1908-1900 on the subject of Mr. Fletcher’s article of Toxins 
produced by plant roots, we read that Dr. Russell criticizes this work 
and says that with regard to the field of experiments, the falling off 
in yield which Mr. Fletcher ascribes to the excretion of toxin sub- 
stances by other plants is no proof that toxin substances are excreted 
and it is generally explained as due to lack of food or water. 
With reference to the water culture experiments it may be 
stated here that Mr. Fletcher obtained a solution of excreta by 
growing plants in water culture and then used this solution as a 
medium for plant growth. He found the medium to be toxic. Dr. 
Russell saj^s that Mr, Fletcher took no precaution to prevent the 
development of bacteria and that there is no evidence to show that 
the toxic substance was excreted by the plant. It might equally well 
have been a bacterial product. Mr. Fletcher’s contention is at 
present not proved. 
Articles on this question of toxins have already appeared in 
the Bulletin. — E d. 
