78 EXPLOITATION OF PLANTS 
disease, and many trees were lost. Here, you might 
almost say, was the first application of science to the 
Brazilian rubber industry, and as has often happened 
in the East, the results were disastrous. We are slowly 
learning that while the native methods of any given 
place may be very bad and very inefficient, they are in 
general the best for the local conditions as they existed 
at the time when these methods were employed ; they 
are open to improvement, but the improvement must 
go hand in hand with that of the other conditions, and 
must be very gradual and cautious. Before the tapping 
knife was employed in Brazil, there should have been a 
series of experiments carried out to determine the best 
way in which to use, and if needful to modify, the new 
tool. As it is, the tappers in the Para district have 
acquired a prejudice against the knife, whereas there is 
little doubt that by its careful and judicious use a large 
number of trees could be tapped which are at present 
left idle as being too small. 
Another problem is the sernamby, or scrap rubber, 
produced in great quantity and of but poor quality ;. 
the collector most often gets the scrap as his pay, and 
so does not make any more fine hard than he must.. 
Yet another great difficulty is the supply of neces- 
saries to the collectors ; little is cultivated up the valley, 
and food and necessaries are supplied by the merchants 
in Para and Manaos, in exchange for the rubber. We 
have already been into this question from the transport 
point of view ; it is merely brought up here to show the 
way in which all parts of the problem hang together. 
The whole problem, so far as Brazil was concerned, 
was much complicated by the high. prices obtained for 
