18 ON THE COMMERCIAL KINDS OF INDIA-RUBBER. 
Roxburgh also found that older trees seemed to yield a richer juice, 
which, when exposed to the air, separated spontaneously into an elastic 
substance or caoutchouc, and a fetid whey-coloured liquid. Tt is col- 
lected by making incisions across the bark to the wood. About 50 
ounces of the pure milk taken from the trees in August yielded 153 
ounces of clean washed caoutchouc. After one operation the tree re- 
quires a fortnight’s rest, when it may be repeated. During the cool 
season, from October till March, the juice is more scanty than in the 
warm weather, from March to October, but richer. Assam rubber is 
shipped from Calcutta in baskets made of split rattans, and weighing 
about 8 ewt. each. These are generally covered with a jute, gunny 
bag. This india-rubber has a peculiar mottled appearance, of a bright 
pinky colour, and very glossy. The baskets consist of either a great 
number of small “balls” pressed together, or a large irregular mass 
called **slab." The former is not so much liked, as it offers greater 
facilities for adulteration than the latter. It is curious to see this 
and other kinds of hard india-rubber sampled at the London wharves, 
etc. as, owing to its resistance, it will only allow of being cut with 
a chopper or knife constantly kept wet with a stream of water. It 
sometimes takes three or four men some considerable time to cut 
out a slab about twelve or fourteen inches long. According to 
Royle, any quantity of rubber can be obtained from India. One 
great fault, however, clings tenaciously, not only to this, but to all 
East Indian varieties—that is, its impurities. There is no reason 
why the caoutchouc of India should not be as pure as fine Para, if 
proper care were taken. In 1836, while Para rubber was selling at 
25. 6d. to 3s. per lb., East India was only selling at 24. !.and, although 
there is more care taken now, yet there is great room for improvement. 
How ignorance may retard the development of a country's resources ! 
In 1828, a zealous collector sent a parcel of rubber from Assam to a 
large agency in Caleutta, but the consignees, at a loss what to do with 
it, sent back the following reply, much to the mortification of the 
collector :—“ The article being unknown in the Calcutta market, we 
are sorry we can give you no idea of its value." 
Java india-rubber has a dark glossy appearance, with occasional 
streaks of a reddish colour. Its price is about Is. 6d. to ls. 8d. per 
lb. I donot know what plant it is produced by; Lindley (Flor. Med. 
p. 298) says, “ It is believed that Java caoutchouc is produced exclu- 
