Indian Forest Records. 
[Vol. III. 
it 
It will be seen that the colour still remained high in spite of the 
addition of myrabolams which should have considerably reduced the 
colour of the resulting extract, the red varying from 17 to 29 and yellow 
from 25 to 46, while! in good extracts, in order to meet market require¬ 
ments, the red should not exceed 10. This is mainly due to the bad 
quality of the water used. As pointed out elsewhere, the colour can be 
reduced by using distilled water even without the addition of myrabolams 
to the required standard. This fact has been fully supported by small 
scale experiments conducted in the Laboratory. In other respects, the 
extract has been pronounced by competent authorities to be fairly good, 
as will be seen from the following letter from Professor Dunstan of the 
Imperial Institute, London, addressed to the Forest Chemist:— 
Letter from Professor Dunstan of the Imperial Institute, London , to the 
Forest Chemist , dated 28th April 1911. 
“ The sample consisted of a solid, brittle, dark brown extract, showing a vitreous 
fracture. This extract was almost completely soluble in cold water # # # 
The extract produced a reddish brown leather of fairly stiff texture. 
This sample of mangrove extract is the best yet received from India for examination 
at the Imperial Institute. It is of good consistency and appearance, does not contain 
excess of moisture, is almost completely soluble in cold water, and is very rich in tannin. 
The percentage of tannin present is higher than samples of Borneo mangrove extract 
at the Imperial Institute, but the extract furnishes a rather darker and redder leather 
than that yielded by good mangrove extract from Borneo.” 
It may be safely stated that the tannin extract made from Burma 
Mangrove barks under the better conditions described in Chapters I and II, 
will be equal to the Borneo Cutch and would command as ready a sale. 
The eighteen tons of extract mentioned above, though not quite so good, 
was valued at £12-65. per ton c. i. f., Glasgow. The quality of the pure 
Mangrove tannin extract would then come up to that of this mixed 
extract with sufficient improvement in its colour, but according to the 
experiments recently carried out the results will be far better if myra¬ 
bolams were mixed with Mangrove bark in the proportion of 1:7 
previous to extraction. This admixture would not only improve the 
colour but eliminate the rather serious defect of harsh tannage on the 
resulting extract, giving softer and lighter leather. 
In conclusion it may be remarked here that a typical tannin extract 
factory must be equipped with an up-to-date machinery capable of 
treating 60 tons of raw materials per day. The erection of such a factory 
259 
