KAURI GUM MINING IN NEW ZEALAND 39 
The so-called kauri gum is really a true resin and not a gum, but 
the latter term has become so generally used that it is here retained. 
The material is a solidified turpentine which exudes from the 
tree as a clear, transparent liquid and hardens rapidly on exposure 
to the air, assuming then a dull white or slightly yellowish appear- 
ance. It collects in large quantities on all parts of the trees, on the 
leaves, in masses on the branches and trunk, and throughout the 
bark. The heaps of bark that peel off and collect on the ground are 
saturated with it and become solidified. These fresh exudations, 
however, supply very little of the gum of commerce, most of the 
latter being a fossil gum which has come from the secretions of the 
kauri trees, and has accumulated in the soil of the forests, or in 
the clay or other formations below the soil. It is of a light or 
dark brown color, sometimes almost black, transparent to trans- 
lucent in luster, generally more or less homogeneous in character, 
but sometimes including leaves, sticks, and insects. There is a 
popular impression in New Zealand that the fossil gum, through 
some process underground, has become purer than the fresh gum 
from the trees. 
Kauri gum occurs both in regions now covered, or which have 
until recently been covered, with kauri forests, and also where 
no kauri trees have been known to grow in historic times, but where 
they existed in bygone ages and have been destroyed by fire, sub- 
mergence, or other causes. In fact, the larger part of the kauri 
gum mined in New Zealand is derived from open country, called 
‘“‘gumfields,” destitute of any considerable timber, while the old 
roots and other parts of trees found under the soil prove that kauri 
forests once existed there. It is generally supposed that in such 
cases the forests were destroyed by fire, and the burned character 
of the remains of the trees found with the gum lends some evidence 
to such an hypothesis. On the other hand, it has been suggested 
that a fire that would destroy a forest would also destroy such an 
inflammable material as the gum; but it must be remembered that 
the gum that had become buried in the soil would be more or less 
protected from fire. Moreover, the gum is so abundant that 
though much of it might be destroyed in a burning forest, yet 
much might escape. 
