INDIAN FOREST RECORDS. 
Vol. III. ] 
1912 
[Part IV. 
Note on the Preparation of Tannin Extracts with special reference to 
those prepared from the bark of Mangrove (Rhizophora mucronata). 
By PURAN SINGH, F.C.S., 
Chemist at the Forest Research Institute, Dehra Dun, India. 
INTRODUCTION. 
U NDER instructions of the Inspector-General of Forests conveyed in 
his. letter No. 1381—79-6, dated 15th August 1908, an investi¬ 
gation into the causes of the objectionable colour of the Mangrove bark 
extract as prepared at the Government Tannin Factory, Rangoon, has 
been carried out by the writer mostly at the Government Tannin Factory, 
with a view to eliminate, if possible, the colouring matter complained of, 
and to form an idea as to the probable commercial prospects of the 
industry of tannin extract manufacture in Burma, chiefly from Mangrove 
barks. 
This note embodies a brief resume of the general processes of tannin 
extract manufacture and the factors which influence the manufacture 
of good extracts, together with a valuation of the Mangrove barks as 
raw materials for tannin extracts. It also discusses the commercial 
prospects of this industry in Burma where a large supply of the raw 
material can be made available from Tavoy, Mergui and Andaman 
Isles. 
In Chapter I of this note, a general description of the processes of 
tannin ex tract ^manufacture is given in order to give an idea of the 
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