KXPEUIMENTS ON OUM PRODUCTION IN KORnOFAN 



77 



an operation which nciMl nut take up very iimch of their time, and in that way it is 



reasonable to suppose that a considerably larger amount of gum per tree would be obtained, 



while the money value of the gum from an acre of well stocked gum garden would well 



repay any extra labour spent in clearing the ground or sowing seed w'here necessary. The 



question of increasing the amount of gum produced in a distiict is comparatively simple, 



as the factors on which the yield of gum depends are to a considerable extent under control, 



such as increasing the number of trees and removing those which are too old to produce 



gum. In view of this it becomes a much more important point to be able to increase Desirability 



the proportion of hard, strong gum which fetches a much higher price than that of lower °^ producmR 



grades. Unfortunately, the factors which underlie the production of this hard gum are but strong gum 



little understood. Dr. Beam has made a special study of this problem, but failed to find 



any of this hard, strong gum in a series of collections made in several gardens at Taiara. 



This may have been due to lack of favourable conditions of temperature and rainfall, wrong 



season of tapping, or other causes mentioned by Dr. Beam in his article on this subject 



in the Third Eeport of these Laboratories. I examined the gum from these two sets of 



trees above-mentioned, but also failed to find any of this strong gum. 



The following table shows the viscosity and acidity of the gum from the two sets of 

 trees, so far as determined ; — 



GUM FROM SMALL TREES 



GUM PROM LARGE TREES 



An attempt was made at first to test the samples immediately after collection, but 

 the tears of gum were tlien so tough that they could not be pounded up, and consequently 

 it was not possible to obtain a fair sample. The mixed guin from each collection was 

 therefore allowed to dry in the air for several weeks, and a fair sample of sufficient 

 size taken for examination as soon as it was found to be dry enough to powder. The 



