Flückiger and Hanbury report that charas yields from onequarter to one-third of its weight of an amorphous resin; it has also been stated that good samples yield 78 per cent. of resin. From the above table it will be seen that in North Indian samples the average yield is 40 per cent. The highest is a sample from Kashgar, and the lowest are the Baluchistan samples, and that made from wild plants grown in Kumaon, the latter being similar in composition to a good sample of ganja. The samples from Amballa, Amritsar, Delhi, and Bombay are remarkably uniform in composition and physical characters, and give evidence of having a common origin such as that of Turkestan. They all contain a large amount of sand. The Gwalior and Himalayan samples have a similar amount of resin as the imported kind, but here the organic impurities are in excess of the inorganic. There is very little difference in the resin content and the appearance of the three Delhi samples, and consequently there is nothing in the proximate composition to account for the money value. The same remark applies to the Baluchistan samples of varying quality, where, strange to say, the amount

of sand is highest in the first-class charas. It would seem that fine sand is inseparable from the glandular hairs that are shaken from plants and collected on a cloth on the floor in the hottest and driest part of the year. The amount of nitrogen throws no light on the quality of charas; it appears to correspond with the insoluble vegetable matter present. The Amballa sample, with 12.9 parts of vegetable débris, gave 0-84 per cent. of nitrogen, while the Gwalior sample, with 27-7 per cent., gave 1-75 per cent. of nitrogen. Extracts of ganja and bhang frequently give reactions for alkaloids, but preparations of charas give very slight, if any, indications of the presence of alkaloids. There is no doubt, therefore, that the active principle resides in the resinous oil extracted by alcohol and other volatile solvents. In a recent paper on The Valuation of Indian Hemp," 1 I have given the results of a preliminary examination of the alcoholic extracts of the three samples of Kashgar charas, since the percentage of resinous oil gave no indication of their commercial value. The amount of essential oil corresponded to the grade, but the highest amount of extract was contained in the lowest quality of charas. The dried extracts were purified by saponification. The amounts of unsaponifiable matter were determined, and their iodine values taken. The iodine value was also taken of the extracts. These tests showed no practical difference in the composition of the extracts, which contain a large proportion of the red oil, cannabinol, discovered by Wood, Spivey, and Easterfield in 1896. The following figures were obtained:

But when extracts of older samples of charas were examined, there was found to be a considerable diminution in the iodine values and percentage of unsaponifiable matter. I have also found this to be the case in testing samples of ganja and bhang of different ages, and I trust that further work in this direction will prove the utility of the iodine method in determining the value of Indian hemp drugs. The chemical examination of the various samples of charas lead to the conclusion that there is no systematic adulteration of the drug. There is a uniform content of 40 per cent. of extract; the vegetable matter consists naturally

1 Pharm. Journ. [4], 27, 80.

of the hairs and portions of the leaves; and a certain amount of sand and mineral water is inseparable from the product as usually prepared.

Physiological Value.-The physiological values of most of the above samples of charas were tested by Captain J. F. Evans, I.M.S., chemical examiner to the Government of Bengal, whose report was published in the proceedings of the Indian Hemp Drugs Commission, 1893-94. The experiments were made with the alcoholic extracts, and it was found that the extract of only one sample, that of the mashak or best charas of Amritsar, approached in definite physiological effects the action of the extract of Bengal ganja which was taken as a standard. Accepting 32 as the value of the Amritsar mashak charas, the inferior physiological values of the other samples are given in the following figures: Delhi mashak, 24; Amballa mashak, 23; Garhwal, 21; Delhi dust, second class, 20; Amritsar bhara, 19; Bombay, 4; Amballa mashak and Delhi dust, 2; Kumaon (wild and cultivated) and Gwalior charas, 1. Here the best Amritsar charas imported from Yarkhand is thirty-two times as potent as Gwalior charas, a drug made by collecting the resin from plants grown in the plains. As with ganja and bhang, the quantity of alcoholic extract was found to bear no relation to the activity of the sample. The samples of Nepal charas proved very unsatisfactory in Captain Evan's experiments. A dose of more than ten grains of the extract administered to a cat weighing less that 4 lb. having produced no effects, he did not consider it worth while to pursue the investigation further. Whether the absence of physiological effects was due to adulteration or the absence of active principle in the hemp plants from which the samples of charas were prepared he could not decide. Considering that the standard extract had been made from fresh ganja, I am inclined to think that the variation in the relative activity of the samples was largely due to the age of the drugs rather than to their origin. This opinion confirms the overwhelming evidence with regard to the potency of fresh samples and the gradual deterioration of crude hemp drugs and their preparations when stored for a long time.

I must acknowledge my indebtedness for the information used in drawing up this paper to the Special Assistant for Chinese Affairs to the Resident of Kashmir, Kashgar; to Mr. R. HughesBuller, Baluchistan; and to the report of the Indian Hemp Drugs Commission.

The PRESIDENT said he was very pleased that Mr. Hooper had contributed this paper to the Conference. The author and himself worked side by side at Bloomsbury Square more years ago than he cared to remember, and he recollected Mr. Hooper as a most enthusiastic student. They all knew, of course, that Indian hemp was of very variable composition, and the difficulty which struck him in connexion with the drug was twofold. There was first the difficulty experienced owing to its variable activity, which was due to cannabinol, and secondly there was difficulty in the fact that some persons were notoriously immune to the action of the drug. The whole subject was, in fact, beset with difficulties. As most of them were aware, Professor Marshall had done a great deal of work on the subject, but he did not think the matter had attracted the attention it deserved. The ultimate solution of the problem would be found in the preparation of an extract of the drug in India, and its importation in closed vessels.

Mr. D. B. DOTT mentioned that some years ago he suggested to his friend Professor Stockman that he should make an investigation regarding Cannabis indica, and he replied that he would not care to do so, as he did not consider it of any medical importance.

Mr. EDMUND WHITE pointed out that there was an analogy between digitalis and Indian hemp, especially in connexion with the method of storage and age. It was well known that the drug varied enormously in its strength owing to the presence of enzymes which brought about some change in the active principle unless stored under conditions which precluded enzyme activity. He considered that it was necessary, in order to get the best results, to have the drug imported as alcoholic extract in small sealed tubes, which could be opened and used quite quickly.

NOTES ON SOME B.P.C. FORMULAS.

BY HAROLD WYATT,

Pharmaceutical Chemist.

In presenting these notes for the consideration of the Conference my only desire is that they may give rise to a discussion, and I trust that they will be accepted simply as records of personal experience, and will not be regarded as embodying any new methods, or describing any new discoveries.

Elixir Pini et Terpini et Acetomorphina.-A better preparation may be made by adding the acetomorphine hydrochloride in solution after filtration of the elixir and before making up to the prescribed volume. The use of 5 per cent. of concentrated infusion of senega ensures non-precipitation of the oil of pine and of the terpin when the elixir is diluted with water on administration. It may be mentioned that the liquid terpinol, used considerably on the Continent in place of terpin hydrate, is more manageable than the hydrate in all these formulas, has a pleasant flavour, and is medicinally as effective as the hydrate. Liquor Seriparus.-Made with fresh rennets according to the following method, an essence results which is superior as regards freedom from smell, and equal in general activity to one made from the dry salted rennets :

Rub the rennet well with the salt; cut it up into small pieces and macerate with 50 of the chloroform water and 10 of glycerin for four days; then add the alcohol and sherry, allow to stand three days, and strain. Next shake with kaolin 2.50, and set aside for a week. Finally, decant the clear solution, filter the remainder, add the lactic acid, and make up to the required volume with chloroform water.

Mistura Senna Composita.-Though this is a pharmacopoeial formula, a note in the Codex concerning the use of aromatic spirit of ammonia in its preparation is the cause of my directing attention to it, and of giving the following as an alternative method, suitable where quantities are wanted for stock :

Mix the magnesium sulphate with the senna, and pour on 50 of boiling water. Stir in the solution of ammonia when the