12 ON THE COMMERCIAL KINDS OF INDIA-RUBBER. 
fluid evaporates, and leaves a hard resinous substance behind, unaf- 
fected by hot water or steam. The rubber itself is jet black in colour, 
though, when purified from its resinous contents, I believe of a whitish 
colour. 
Of those above mentioned, two—namely, Guayaquil and Guatemala 
—are, without doubt, the produce of Castilloa elastica. The so-called 
West India is also produced by the same plant. As to Carthagena 
rubber, if analogy of character be any criterion, I should say that, in 
all probability, it was also derived from Castil/oa elastica. How- 
ever, Dr. Spruce says, “I have often been told of a pinnate-leaved 
tree, yielding caoutchouc, which I could never fall in with. I am, 
therefore, unable to guess even at the family to which it belongs ; 
but there is said to be such a one about Serpa, on the Amazon, and the 
same (or a cognate species) in some inland region of New Granada or 
Venezuela, whence it finds its way to Carthagena." 
With regard to Honduras there may be a little doubt, on account of 
the character ; but this may be the result of chemical treatment. 
The following information has been supplied by M. Diezmann, of 
Greytown, Nicaragua, to Mr. John Collinson, C.E. :— 
“*Ule’ (or ‘Tassa’ of the Mosquito Indians) is an important 
article of export from Nicaragua; and San Juan del Norte, or Grey- 
town, is the principal port whence it is shipped. Having for many 
years dealt in it, and having never seen a correct account of the 
manner in which it is collected and manufactured, I shall offer a few 
remarks on the subject. Expeditions for collecting Ule, or Nicaraguan 
india-rubber, are organized by a number of men clubbing together, 
and applying to one of the india-rubber dealers to furnish them 
with the necessary outfit, including provisions, blankets, machetes, axes, 
pans, pails, buckets, etc. They bind themselves before the local autho- 
rities to work a certain time for the dealer, and deliver to him the pro- 
duce of their work. This formality gone through, the men—or Uleros, 
. as they are now called—generally have a series of amusements, danc- 
ing, drinking, and gambling, until the dealer intimates to them that 
their departure ought not to be delayed any longer. All the necessary 
things are now embarked, and under the blowing of conch-shells and 
shouts of friends, the canoe shoves off. Often the poor fellows have 
to travel a fortnight before they arrive at their destination,—passing 
rocks and rapids, and being frequently compelled to unload their canoe 
