302 
Indian Forest Records. 
[VoL. I. 
the globules taking place first through pestling or stirring the sub- 
stance), and finally these aggregations of gum particles cohere into 
semi-solid adhesive masses, which act as a sort of binding material 
between the already densely-scattered resinous and other globules, 
thus thickening the whole mixture. On the other hand, when the 
thickened varnish is gently heated or is ground down with camphor, 
the solid adhesive masses of the gum melt or break up, giving off 
water which they had absorbed and thus gradually reducing to 
their original state. In this way, the gum particles themselves and 
the resinous and other globules are left free to move about, and the 
thickened varnish is broiight once more to its original liquid condi- 
tion. 
Essential Conditions for the Drying Process. 
In order to determine the essential conditions for the drying of 
the varnish, drying experiments were made with the original juice 
and various mixtures of its several constituents iinder different 
conditions. These experiments some of which have already been 
mentioned under examination of the constituents are summarised in 
the following table : — (For the purpose of shortening the period 
of drying only a very thin layer of the experimental material coated 
on a glass plate was exposed to the actidn of the air.) 
