( IB ) 
9. Njatoh Dujan. 
Palaquium Treuhii Burck. 
A Borneo species producing an inferior gutta, 
which is “ bluish white with a dirty grey almost 
black surface. The section shows a compact hard 
mass which is not very elastic. Although it is fairly 
coherent, pieces can be broken off with a little force. 
The fracture shows a granular surface. By adding 
inferior kinds these qualities gradually change. 
Often used to adulterate better grades of gutta and 
it is also adulterated with inferior things, parti- 
cularly jelutong.” 
10. Njatoh Renkeng. 
Palaquium xanthochymum Pierre. 
A yellowish second class gutta from the Malay 
Peninsula. 
11. Mentua Taban, Taban Pertja, Getah Pertja. 
Payena Maingayi Clarke. 
This is a species of the Malay Peninsula which is 
sometimes credited with having furnished the name 
for gutta percha. The gutta is of poor quality and 
practically worthless. 
It is probable that a number of other inferior 
guttas are used, but our knowledge of them is very 
incomplete. 
Mention should be made of certain substances 
which are not true guttas, but which are sometimes 
mixed with gutta percha, to increase its bulk, or 
are substituted for it. 
