L7
COMMERCIAL INVESTIGATIONS.
Lists of the vegetable drugs of Hongkong, samples of many of which had already been forwarded, were sent to the Director of the Imperial Institute, London, for a report as to whether any of them contained medicinal or toxic qualities, or had economic value. These lists were submitted by the Director of the Imperial Institute to the British Pharmacopoeia Committee of the General Medical Council, the Secretary of which replied that the Committee did not feel there were sufficient indications of the extent of employment of individual plants to say which, if any, should merit inclusion in the Colonial Addendum to the British Pharmacopoeia. The Director of the Imperial Institute added that he did not think any of the plants in the list were likely to yield products of economic value not already known.
The Government is greatly indebted to Dr. Ho Kai for supplying valuable information in regard to these drugs, without which the investigations would have taken years to complete.
Seeds of Aleurites Fordii, Aleurites cordata, Aleurites triloba, Soja hispida, Perilla ocymoides and barks of the above three species of Aleurites, as well as several kinds of vegetable oils, were also sent to the Director of the Imperial Institute for a report as to their commercial value and suitability for the English market.
Professor Dunstan reported that the bark of Aleurites Fordii could be used locally as a tanning agent and would yield leather of fair quality, especially if employed in admixture with a mellower and richer tanning material, such as myrabolans, but that the barks of the other two species were useless as tanning agents.
The following are Professor Dunstan's general conclusions on the three species:-
"The suggestion that the barks of Aleurites cordata and Aleurites Fordii might be examined as tanning materials was made in a letter dated 21st May, 1909, from the Imperial Institute to the Superintendent of the Botanical and Forestry Department at Hongkong as the result of statements made in German technical journals, that the bark of Aleurites cordata is rich in tannin. A similar assertion has recently been made regarding the bark of Aleurites moluccana (Aleurites triloba).
The results now recorded do not bear out these statements, since neither the bark of Aleurites cordata nor that of Aleurites triloba contains enough tannin to make it suitable for use as tanning material, whilst the amount of tannin present in the bark of Aleurites Fordii is small. Of the three barks, only that of Aleurites Fordii could be used for tanning, but even this material contains too little tannin to be worth exporting and it would only be suitable for local use.
It seems unlikely that the present results differ from those previously recorded owing to differences in the ages of the trees yielding the barks. The three samples of bark forwarded from Hongkong were apparently obtained from fairly old trees, and as a rule the percentage of tannin in the bark increases with the age of the tree. It is therefore improbable that the deficiency of tannin in the present specimens is due to collection at too early a stage.