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27TH JUNE 1895, No. 407, REVENUE.
in potash. With regard to this plant it should be noticed that it contains a poisonous alkaloid,
erythrine, which would render it injurious to cattle if they fed upon the leaves in any quantity.
The blistering property of the Holigarna.— The Holigarnas are large forest trees growing
in Southern India and Burma, and the bark and fruit yield a black varnish in the dry weather
which blisters the skin. This irritating secretion has been noticed by several forest officials,
but the cause of this peculiar property has not hitherto been investigated. Some fresh fruits
of Holigarna ferruginea having been forwarded from Travancore, I made an examination of
them and found the vesicating principle to be due to a very acrid oily liquid resembling
cardol. Cardol is a constituent of the marking nut and the cashew-nut, both belonging to the
same natural order, Anacardiaceæ, and it is probably contained in other acrid juices yielded by
trees of this order.
Osyris arborea.—This shrub, which is common on the Nilgiris as well as the Himalayas,
was at one time the source of the Maun or Bischar Tea mentioned in Moorcroft's Travels in
Tibet. The leaves have not an unpleasant odour when dried, but they are said to be very
nauseous, especially if used in a fresh state. In preparing the tea the leaves were infused in
hot water and then taken out and dried in the sun. The first infusion removed the emetic
principle and subsequent treatment with hot water afforded a palatable drink. I submitted
some of these leaves to a chemical examination and found the chief constituent to be tannic
acid, which amounted to over 20 per cent. There was no alkaloid present in the leaves, nor
any principle that would render their infusion a stimulating beverage like that of tea or coffee.
Dock root.—During the improvements of the Ootacamund lake margin by the removal of
weeds and undergrowth, a large number of plants of the Indian dock ( Rumex Nepalensis ) were
uprooted. This dock has a yellow root which contains a large quantity of colouring matter.
The root has the odour of rhubarb root, and, according to Dr. Irvine, it is sold in the bazaars
of Bengal under the name of Rewund chini as a substitute for medicinal rhubarb. The roots
contain an appreciable quantity of chrysophanic acid, a substance for which there is a consider-
able demand. In order to ascertain if the roots could be used as a profitable source of this
acid, I have sent samples to Mr. Perkin of the Yorkshire College, Leeds, and to Dr. Hesse of
Stuttgart who have made vegetable colouring matters a special study.
Experiments with Trichinopoly Phosphates as manure.—Some interesting experiments have
been conducted during the past six months with the powdered phosphatic nodules of Trichino-
poly applied to different plants. It is well known that the soils of the Nilgiris and the Wynaad
are very deficient in lime and phosphoric acid, the two main constituents of mineral. phosphates,
and it would follow that the applications of such a substance would be very desirable to the soil
on these hills where heavy crops are grown. Bones, fish, and poonacs are expensive manures
in most of the planting districts in Southern India, and as the recently discovered nodules
appear to be abundant, there will doubtless be a demand for them among planters when their
value becomes better known. Enquiry has often been made as to the method of applying the
phosphate. The best form in which phosphate of lime is available for the plant of course is
soluble phosphate or superphosphate; but the present high cost of sulphuric acid in India,
compared with its price in England, is a great hindrance to the local manufacture of a good
superphosphate. In my experiments both the soluble and raw insoluble phosphates have been
used and some very good results have already been obtained with the use of the raw powdered
nodules. The full results of these experiments will form the subject of a special report and
will include the analyses of different samples of the Trichinopoly phosphatic, nodules and the
analyses of plants treated with this manure compared with their analyses when grown in
ordinary soil,