over-dose produces tetanus and death; a medicinal one (of a grain three times a day, for example) restores the sensation of paralytic limbs, and has sometimes accomplished a cure in very desperate cases.

The salts of strychnine, that is, the products formed by its combinations with acids, are even more active than their base. The sulphate of strychnine produces marked effects in doses of of a grain.

One of Dr. Bardsley's patients in Lancashire, who was experiencing the return of sensation in his paralysed limbs under the use of strychnine, asked if there was not something quick in the pills; quick for alive being still in use in that part of England.

Brucine. There are some interesting points in the history of this alkaloïd. One of the best vegetable tonics is the Cusparia bark, formerly called Angustura bark. Something, however, which resembled it sufficiently to pass for it, was found to be so poisonous that in several Continental states all the stores of Angustura bark were ordered to be burnt. It was discovered, on accurate examination, that the genuine drug had been mixed with another bark possessing poisonous qualities, and that in some samples the false Angustura alone was present. This destructive substitute was the bark of the brucea antidysenterica, or, according to others, of some species of strychnos. In 1819, MM. Pelletier and Caventou discovered brucine in the bark of the brucea antidysenterica; it is an alkaloïd which possesses in a less degree the remarkable powers of strychnine. Like strychnine, it stimulates the spinal cord and produces tetanus; but twelve grains of brucine are scarcely equal to one of the more potent alkaloïd. The two substances, as we before remarked, exist together in the various species of strychnos; and Majendie remarks that, in the faba St. Ignatii and the upas Tieuté, brucine plays the same part with reference to strychnine, that cinchonine does with reference to quinine; for the strongest kinds of Peruvian bark contain the greatest proportion of quinine, just as the St. Ignatius's bean and the upas Tieuté, which are much more active than the nux vomica, contain much strychnine and little brucine:

in the upas Tieuté, indeed, the strychnine is almost pure.

Morphia. Of all narcotics, opium is unquestionably the most valuable; yet it has some attendant disadvantages; it constipates, and often causes head-ache. Attempts had long been made to separate the good and evil principles of opium; and the black drop, the liquor opii sedativus, and other preparations, had in some degree effected their object. The discovery of morphia is another step gained in this important investigation. morphia is almost insoluble, it is usually combined with acetic, or sulphuric, or muriatic acid; so that it is the acetate, or sulphate, or muriate of morphia which is administered. A quarter of a grain of any of these salts is perhaps equal to a grain of opium.*

As

Another principle, which promises to be useful, was discovered in opium about three years since. It is named codeine, from kædeιa, a poppy-head. Codeine is less. powerful than morphia, but has succeeded, according to Majendie, in cases where every other therapeutic agent had failed.

Emetine. This is the principle to which ipecacuanha owes its emetic powers; it may also be procured from the root of the violet. Emetine, when perfectly pure, is a medicine of great power, two grains being sufficient to

* As some few of our readers may wish to know how these new abridgments of medicine are procured, we will give as an example M. Robiquet's method of obtaining morphia.

A very concentrated solution of opium is boiled for a quarter of an hour with a little magnesia, in the proportion of about two hundred grains of magnesia to a pound of opium. An abundant greyish precipitate is formed, which is filtered, and washed with cold water. It is then dried, and digested in weak alcohol, which is kept hot, but not allowed to boil. But little morphia and much colouring matter are thus removed. The precipitate, after having been again filtered and washed with a little cold alcohol, is boiled in highly rectified alcohol. The solution is filtered while hot, and as it cools it deposits crystallized morphia, which is deprived of its colouring matter by repeated crystallizations, and the employment of animal charcoal,

kill a large dog. A sixteenth or an eighth of a grain is sometimes sufficient to cause vomiting in a man. Like ipecacuanha, it is used as a cough medicine, in which case the doses are of course very small. Thus Majendie recommends eight grains of pure emetine and four ounces of sugar to be made into nine-grain lozenges, each of which will contain about of a grain of pure emetine.

The Febrifuge Alkalies.-Two of these are contained in cinchona (Peruvian bark), one being called cinchonine, and the other quinine; both of these are present in many kinds of cinchona, but the absolute quantity of both, as well as the relative quantity of each, vary extremely in different species. Thus, in a pound of one species Dr. Michaelis found thirty-two grains of cinchonine and sixty-four of quinine; in a pound of another, eighteen grains of cinchonine and eight of quinine; and in a pound of another, two hundred and eighty-six of quinine and no cinchonine.

Both these alkalies possess, like cinchona, the power of curing ague: the quinine is by far the most used; but, as it is scarcely soluble in water, it is the sulphate of quinine which is commonly prescribed. The sulphate of quinine dissolves in water, slightly acidulated with sulphuric acid, and with the addition of tincture of orangepeel forms an elegant though intensely bitter mixture.

The sulphate of quinine, when exposed to the temperature of boiling water for some time, becomes luminous and highly electrical; the sulphate of cinchonine possesses the same properties in a less degree.

These alkalies are certainly valuable additions to the materia medica; for many patients who could not, or would not, take cinchona in substance, can easily digest two grains of the sulphate of quinine. It is in vain, however, to imagine, with some enthusiastic physicians, that cinchona can be entirely discarded; partly because the alkalies which they would substitute are much more expensive, and partly because it is not always advanta

* 66 Quel praticien donnerait aujourd'hui le quinquina en poudre ou en extrait, de préférence au sulfate de quinine ou a la salicine?"-Majendie.

geous to get rid of the other principles with which the alkalies are associated in cinchona. Nevertheless, fruitful as modern analysis has been in discoveries of this kind, it may be doubted whether any one of them, even morphia itself, is more important than that of quinine.

Salicine.-This is another febrifuge medicine; it is obtained from the bark of the willow. The dose is about twelve grains in the four-and-twenty hours. It sometimes succeeds when the sulphate of quinine has failed, and vice versa. - Ilicine, derived from the ilex aquifolium (common holly), is also said to cure agues. It is remarkable that, in the language of medicine, febrifuge signifies curing agues and not curing continued fever: the reason probably being, that at the time when this word received its acceptation, agues were the commonest kind of fever; the reverse being the fact at present.

Veratrine.-Four-and-twenty years ago, when the eau médicinale d'Husson was at the acme of its reputation, Mr. James Moore wrote two letters, in which he endeavoured to show, by a number of curious facts, that this specific for the gout was indebted for its powers to white hellebore (veratrum album). It afterwards appeared that the bulb of the meadow-saffron (colchicum autumnale), and not the white hellebore, was the principal ingredient. Mr. Moore's ingenious supposition, however, though wrong in form, was right in substance ; for the veratrum and the colchicum both owe their virtue to the same alkaloïd - veratrine.

This potent remedy acts with extreme violence even in very minute doses, and its effects are most marked when applied to a mucous membrane. A small quantity put into the mouth excites most abundant salivation; if snuffed up into the nose, it causes sneezing of dangerous intensity; a quarter of a grain introduced into the intestinal canal produces abundant evacuations.

Majendie once gave two grains of veratrine, within four-and-twenty hours, to a patient without producing hypercatharsis; but then in this case the patient was a man who had had an apoplectic fit some time before. Majendie justly cites this as an instance of the way in

which the effects of medicines are modified by the state of the nervous system; for he himself, having only tasted the potion which contained the two grains, experienced for several hours an insupportable acrimony in his mouth and pharynx, which was not quite gone on the following day: the patient had not felt anything of the kind.

An ointment made with four grains of veratrine to the ounce, may be employed externally in cases of tic douleureux or obstinate chronic rheumatism. It is a violent and unmanageable remedy in all its forms.

Prussic acid.-This most dangerous of all medicines was discovered by Scheele in 1780, but was first used by Professor Brera of Padua in 1809. It derives its name from having been originally made from Prussian blue; and, in like manner, its synonym hydrocyanic (acid) is derived from dwp, water, and Kvavos, blue. A single drop of pure Prussic acid is sufficient to kill a strong dog; but what is commonly called by that name is much diluted, sometimes containing only three per cent. of real acid. Even this, however, is dangerously and destructively powerful, requiring such caution in the prescriber and compounder as is not always to be found. Several of the French forms of Prussic acid are exceedingly strong, and it unfortunately happens that there is a syrup of hydrocyanic acid in the Parisian codex (pharmacopoeia) much stronger than one of the same name in common use. Some years since, seven epileptic patients, in one of the Parisian hospitals, lost their lives from this cause. Their physician had prescribed a moderate dose of the syrup, meaning the common one; but the attendant administered the syrup of the codex, and in three quarters of an hour the unhappy victims of a defective nomenclature were no more. It is to Prussic acid that bitter almonds, laurel-leaves, peach-blossoms, &c. &c., owe their poisonous qualities.

Iodine is an elementary substance, discovered by M. Courtois in 1813. It is obtained from the mother-water of kelp, but exists also in sponge and a great number of sea-weeds. Iodine is of a bluish-black colour, resembling bits of shining coal, with which it is said to be some