396 
might be found better to add creosote in the latex, and simply cure 
the biscuits in that form. Mr. Parkinson who worked out the 
methods of making biscuits in 1898 used creosote and if they refer- 
red to a circular issued in that year they would find that he had 
calculated the amount of acetic acid and creosote to be used. They 
kept the biscuits and except some surface mould — they had kept 
their light colour for years together. He thought on the whole to 
add a little creosote to the milk and then coagulate it would perhaps 
make the rubber better to handle. ” 
The experiment of creosoting latex was one of the earliest 
attempted here. The fresh latex was mixed with a little creosote 
and dried naturally in block, without the use of acetic acid. The 
idea was that the darkening of the colour of the rubber was due to 
bacterial or fungal action and the creosote would disinfect it and 
keep it light colored. With a very little creosote it was found that 
the rubber did remain a little lighter in colour. With more creosote 
it was not much improved and it went tacky and was spoiled. It 
seemed to have no useful action on the rubber, and except in very 
small quantities was injurious ; whereupon this experiment was 
abandoned. 
H. N. R. 
DISEASES OF HEVEA BRASILIENSIS. 
Leaf Diseases — The leaves of seedling Hevea brasiltensts, are 
extremely liable to injury by mechanical means or by fungi. These 
injuries are usually local, ie., they affect a small part of the leaf 
only and do not interfere with the functions of the remaining tissue. 
The appearance of a diseased leaf depends to a great extent upon 
the structure of the leaf itself, and in the present case practically all 
injuries cause a whitish semi-transparent area bordered by a brown 
line. Leaves of older plants appear to be immune to most of the 
fungi which attack seedlings. The commonest leaf fungus is that of 
Gray Blight, Pestalozzia Guepini, Desm., this is comparatively 
harmless on leaves, but kills the seedlings when it attacks the stem 
at the collar ; the diseased patch usually takes the form of a white 
ring surrounding the stem, bordered bv a narrow red brown line. 
Equally abundant, but of still less importance, are the leaf spots 
caused by Helmintkosporium hevess, n. sp. ; these are small, circular, 
semi-transparent, and bordered by a purple-brown line. In one 
instance in which the first leaves of seedlings turned yellow and 
dropped off, two fungi, which have been named Gloeosporium brun- 
neum and Colletotrichmn heveae } were found on the leaves. Phyl- 
losticta heveae, Zirgm., and Gloeosporium elasticse, Ckr. & Mass., 
have also been observed. 
Root Diseases. — The first specimens of root disease were for- 
warded to Peradeniya as examples of the damage caused by white 
ants. In old trees the fungus attacks the tap root; this is sub- 
sequently eaten by termites. The free, however, continues to 
obtain a sufficient supply of water from the side roots until it is 
