The aqueous solution also lessens the pain of open cancer, when cloths soaked in it are laid over the sore; and it is as useful in lacerated wounds of tendinous and aponeurotic parts.

1 Observations on the Administration and Utility of Purgative Medicines, etc. 86. 2 Denman. Bland.

3 Pearsons Observations, etc. on Articles used in the Cure of Lues Venerea, p. 60.

With respect to the influence of the components of opium, separately administered, and of their salts, much might be said, did the nature of this work permit me to dilate on particular subjects. The value of Morphia and its salts are fully stated in the third part. (See Morphia and Morphiae Hydro-chloras.) Narcotina was found by Majendie to operate as an excitant on dogs; but on the human subject it produces no excitant effects; at least none were perceived by M. Baily when it was given in doses of sixty grains; and Orfila ascertained that this is the case even when it is combined with acetic acid. It has, nevertheless, been prescribed with apparent advantage as an antiperiodic in ague. Codeia, according to the observations of M. Barbiere, in its uncombined state, seems to operate on the nervous plexus of the great sympathetic as an anodyne, allaying pain in morbid affections of parts connected with that plexus. It neither quickened the pulse, nor disturbed the digestive function, nor caused constipation: and in causing sleep, when given in large doses, it did not affect the head like opium. When combined with acids, it excites, and the collapse which follows closely resembles that caused by the excitement of ardent spirits.

The influence of Meconina on the animal economy has not been examined; nor is any thing known of the influence of Narceia. Meconic acid exerts no action on the living body.

Opium is generally exhibited either in substance as a pill, or under the form of tincture, and externally in that of infusion. It is necessary to avoid combining it with substances which decompose it; and therefore solutions of bichloride of mercury, acetate of lead, sulphates of zinc, of iron, and of copper; of the carbonates of alkalies, lime-water, infusion of galls, and infusion of yellow cinchona bark, and of all astringent vegetables, are incompatible in prescriptions with opium. In combination, however, with vinegar, the vegetable acids, and oil, its narcotic power is much increased, owing to the combination of the morphia with the acids, forming more active salts than the bimeconate of the opium.' The result of my own experience inclines me to regard the acetate as well adapted for cases of phthisis and inflammatory affections, where it is of importance to obtain the sedative effect of the remedy free from the exciting quality.

The dose of opium should be regulated by the nature of the disease, and the peculiar intention for which it is ordered. The circumstance of the patient having been previously accustomed to its use must also regulate the extent of the dose; for in this case a dose, which to one unaccustomed to its use would prove fatal, may perhaps to another in the habit of taking it be scarcely sufficient to produce its narcotic effects. A quarter of a grain, or even less, frequently repeated, is, in general, sufficient to keep up its stimulant influence; and from gr. j. to grs. ij. act as an anodyne, and produce sleep; while in tetanus, hydrophobia, and some other diseases, f vss. of the officinal tincture have been given in twenty-six hours, without occasioning any bad effects, or even producing sleep.2

The use of opium for the purpose of exhilarating the spirits has long been common in Turkey, Syria, and Chinal; and of late years it has been unfortunately adopted by many, particularly females, in this country. Russell2 says, that in Syria, when combined with spices and aromatics, he has known it taken to the amount of 3 iij. in twenty-four hours. Its habitual use cannot be too much reprobated. It impairs the digestive organs, consequently the vigour of the whole body, and destroys also gradually the mental energies. The effects of opium on those addicted to its use, says Russell, are at first obstinate costiveness, succeeded by diarrhoea and flatulence, with loss of appetite and a sottish appearance: the memory soon fails; the individuals become prematurely old, and then sink into the grave, objects of scorn and pity.3

1 The effects of vegetable acids in augmenting the efficacy of opium is displayed in the great power of that preparation of opium, which has been known, for upwards of a hundred years, under the name of "Black Drop." The following is the mode of preparing it, as published by Dr. Armstrong (vide Practical Illustrations of Typhus), from the papers of the late Edward Walton, of Sunderland, one of the near relations of Edward Tonstall, of Bishop's Auckland, by whom it was originally prepared. "Take half a pound of opium sliced; three pints of good verjuice; one and a half ounce of nutmegs; half an ounce of saffron. Boil them to a proper thickness, then add a quarter of a pound of sugar, and two spoonsful of yeast. Set the whole in a warm place near the fire six or eight weeks, then place it in the open air until it becomes a syrup; lastly, decant, filter, and bottle it up, adding a little sugar to each bottle." One drop of this preparation is calculated to be equal to three drops of the Tincture of Opium of the London College. It evidently owes its efficacy to the acetate of morphia : which is formed by the verjuice decomposing the bimeconate of the opium. The acetate itself is a more elegant preparation; and produces its effects in doses of 1/2 a grain.

There is also some reason for thinking that another preparation of opium, the Liquor Opii Sedations, of Mr. Batley, of Fore Street, London, which has been justly esteemed an excellent preparation of the drug, owes its efficacy to the acetate of morphia. The mode of preparing it is as yet kept secret; but I know that the whole of the resinous part of the opium employed is separated and rejected; and probably acetic acid is employed to separate the gummy part. Dr. Paris (Pharmacologia) states as an objection to this preparation, that it undergoes some important change on being kept. Justice obliges me to say, that my experience does not allow me to concur in this remark. I used the remedy before it was sold to the Profession, and I gave it the name it bears; and although I have, since, constantly prescribed it, and kept the preparation in rather a warm situation, yet I have not observed the change of which Dr. Paris has spoken.

2 Currie's Medical Reports, etc, i. 138.