19 
His account continues: “The morphological relations and 
general Aro eorth of the cells which give rise to the substance, 
fluid or living, which, through Dr. Henry’s kind offices, there is 
probability. we may soon receive.” 
PM the promised specimens arrived (now Prof.) 
. E. Weiss undertook the examination of aiken aii from the 
xt dp of his investigations, published in the Transactions of the 
Linnean Society A M 2, Botany, iii, p. 243), the following 
sentences are dra 
* The threads M Po consist of caoutchoue, for they are 
insoluble in alcohol, acids and alkalis, though they become soft 
when treated with rur They dissolve a chloroform and 
turpentine, and swell up in ether. When heated they melt, and 
they burn with the ohar iico gna smell of büritüg rubber 
* From the bark the arie can very readily be extracted. If 
the bark be broken in pieces and pounded in a mortar, the mass 
can be roughly sepa ut n into two parts, one consisting of the 
tangled elastic threads, with small bits of broken bark adhering to 
them, the other chiefly of bits of bark containing, no doubt, smaller 
pieces of the threads. From both parts chloroform will ‘dissolve 
out caoutchouc, a larger amount naturally from the portion which 
consists chiefly of the threads. Thusa kn ga u? the threads and 
bark weighing 443 mg. gave as much as 25 of c acc this 
while the remaining bark, weighing 607 3 mg., yielded onfy 6 mg. 
Taking the two quantities together, the yield of caoutchouc was 
3 per cent. of the weight of the dry bark, and the same figure w 
arrived at independently by Prof. F. W. Oliver with iio 
sample. 
“ The threads are clear and homogeneous, and the only impurity 
= the chloroform extract seems to be a little resin, which can be 
ashed out with alcohol. 
* Whether the bark can be made use of commercially I must 
leave to those who are more experienced in technical matters. 
“The distribution of the caoutchouc-containing cells I had 
been able to determine from the dry material which I first 
ination of the material preserved in alcohol. They occur in the 
inner portions of the cortex, very much in the position in which 
the latex cells of Euphorbia are ouii pm are even more frequent 
in the secondary phloem, where they run between the companion 
cells, and in both cases present the appearanee of very long 
narrow cells, attaining such a length that one only occasionally 
finds their ends. 
* In the leaf a group of caoutchouc-containing cells wie ie 
the ramifying fibro-vaseular bundles, running just w ihe 
phloem, while in the petiole and all along the bunila of the 
midrib they form two groups at the sides of the bundle, and do 
not run below it. 
“ The pe carp of Eucommia, which resembles in appearance 
that of ud end is especially rich in these caoutchouc-containing 
25781 B2 
