IS 
Indian Forest Records. 
[VOL. III. 
CHAPTER UK. 
Defects of Extracts that have been experimentally manufactured in 
Burma. 
Mangrove tannin extract has for some years been manufactured 
experimentally in Burma in fairly large quantities and has been put 
on the English market for valuation. A summary of trade objections 
against the extracts thus made may appropriately be given here. 
The Burma extract is much richer in tannin than the Borneo Cutch 
which is the best brand of Mangrove extract on the market and is 
evidently made from harks somewhat poorer in tannin than the Burma 
barks, but this higher percentage of tannin is nullified by an excessive 
amount of colour. Another great objection was the excess of moisture 
in the Burma extract on account of which it became “ mouldy 99 being 
white and apparently perished on the top. It tanned harsh, giving dark 
leather. It had large amount of insoluble matter which was the general 
objection. 
The chief cause of these defects in the extract have now been 
traced to the alkaline and saline nature of the water used in the 
preparation of the samples. The water used coming from an artesian 
well, when concentrated to a small bulk gave a distinct alkaline reaction. 
Its saline nature is evident from the following analysis : — 
Total alkali . . 
Total chlorine 
Total mineral matter . 
C *044 grm. per litre (in terms of Na 2 C0 3 ). 
C '0416 grm. per litre (in terms of CaC0 3 ). 
. '0381 grm. of chlorine per litre ('063 grm. of 
NaCl per litre). 
. T52 grm. per litre. 
The qualitative tests showed the presence of sodium, calcium, 
chlorine, carbon dioxide and sulphates. 
The colour of the extract and the percentage of the insolubles in 
it cannot he controlled unless the extract is manufactured with distilled 
water and under better conditions of refrigeration. 
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