258 
NOTES. 
becomes sticky and loses most of its value ; sample 5, which was dried 
on the tree in more or less sunlight, was thus deteriorated. 
In conclusion, the opportunity may be again taken of calling 
attention to some misprints which unfortunately escaped correction in 
Mr. Parkin’s paper quoted (Circ. E. B. G., I.). On page 148, bottom 
paragraph, the figures should read 0*9, 3’9, 0'25, and 8‘0 respectively, 
and on page 152, paragraph 2, 0-83 per cent, mercuric chloride instead 
of 8-3 per cent. 
J. C. WILLIS. 
Not® on the Product of the Latex of the Jak 
(Artocarpus integrifolia). 
As is well known, the jak tree exudes when tapped a large quantity 
of a sticky milk, which hardens into a brittle substance. Inquiries are 
frequently made as to whether this substance has any value for rubber 
purposes. It is so brittle that it is evidently of no use for any of the 
ordinary purposes for which rubber is employed, but it seemed to me 
that it might have a value for ebonitising or such purposes. With this 
in view I sent samples to MM. Michelin et Cie. of Clermont Ferrand, 
who have kindly reported on it as follows : - “ A whitish resin, con- 
taining 1‘8 per cent, of moisture. Melts completely in boiling water, 
dissolves in benzine without previous swelling ; on addition of alcohol 
the products precipitated in small quantity from this liquid do not 
agglomerate. On a platinum foil it disengages an odour of burnt 
bread. These characters indicate the absence of caoutchouc or anal- 
ogous bodies (gutta-percha or balata). We do not think that this 
product is of any value in the rubber industry.” 
J. C. WILLIS. 
Pith for Microscopists. 
In Ceylon microscopists have hitherto relied, almost solely, upon 
the pith obtained from the Elder and imported into this Island. It has 
been a common experience when preparing serial hand sections to find 
the local supply of pith exhausted, and this has invariably resulted in 
an unsatisfactory series being prepared. The commercial material used 
for making topees is too soft and fibrous, and one has had to fall back 
upon the tubers of Solanum and Helianthus in cases of emergency. 
When I was up-country a short time ago I came across cultivated 
specimens of Fatsia papyrifera, Hook., known also as Aralia papyrifera, 
or the Japanese rice paper plant. This plant yields an excellent pith, 
which has long been used in China and Malaya for making paper and 
artificial flowers. Though introduced into Ceylon about 1856, its 
