Our yellow and red arsenics are artificial, being no other than the white, mixed with different proportions of sulphur. The white is the strongest, the yellow weaker, and the red weakest. See Auripigmentum and Realgar.

By the use of arsenic in these forms, the ancient physicians were not aware of its destructively stimulant powers. Yet so early as the 13th century, Theodore, a Venetian surgeon, applied it to scrofulous tumours; and, in the next century, Guido used it as a caustic to produce an eschar in scrofula; and, moistened with vinegar, it was applied afterwards not only to scrofulous tumours, but to the spinae pedum (corns). It was afterwards used as an application to cancers; and, with additions of the most singular and ridiculous nature, of qualities the most opposite, it has formed the basis of many remedies for cancer and scrofula. Arum nitre, salt of soot, quick lime, opium, aqua fortis, vinegar, ceruse, blue vitriol, the ashes of burnt (old) shoes, pulp of carrots, hemlock, and bark, are a few only of the remedies united with arsenic, either to correct its acrimony or add to its virtues. Had we room to follow this part of the subject minutely, we could trace the source of some popular remedies in authors now seldom read or known.

In the early part of the present century, when the rage for finding medicines of peculiar activity among the poisons was prevalent, arsenic began to be employed. We have not been able to trace its use in any work earlier than that of Friccius, published at Vienna in 1710; yet we suspect it was used earlier, since we are dissuaded from its use by Sparling, whose dissertation on arsenic was published at Wirtemberg, in 1685. Since, however, the time of Friccius, though Stahl, Wedel, Boerhaave, and Storch, have violendy opposed its use; though various authors have found it dangerous, inefficacious, or hurtful, the practice has continued.

It seems to have been first externally recommended in cancers, generally accompanied with opium; and it certainly produces at times a salutary change in the appearance of the sore. We have had reason to regret that this change is not permanent. Various forms have been employed for the external use of arsenic. Hahneman proposes to give it dissolved only in water, and this probably is the best method"; but the dose should not exceed one-sixteenth of a grain, or rather at first it may be one-eighteenth or one-twentieth, for different constitutions are variously affected with this metal.

Mr. Justamond's applications to cancer, originally derived from the information of a receipt preserved in the Earl of Arundel's family, were little varied: they are generally combinations of arsenic and sulphur. The Earl of Arundel's receipt directs an ounce of yellow arsenic, with half that quantity of Armenian bole, and sometimes as much red precipitate. He employed also a sulphuret of arsenic, and a combination of this sul-phuret with crude antimony. The arsenical preparation which he preferred was scraped and laid on the middle of the sore, while the edges of the wound were moistened with a combination of muriated iron and sal ammoniac. The effects were to correct the stench, to meliorate the appearance of the sore, and to promote the separation of the entire gland.

Miss Plunkenet's receipt is said to consist of the leaves of the ranunculus acris, the greater crow foot, and the flammula vulgaris, the lesser crow foot, a species also of ranunculus: an ounce of each is to be bruised, and added to a drachm of arsenic and five scruples of sulphur. The whole is to be beaten into a paste, formed into balls and dried in the sun. When used, they are beaten up with the yolk of an egg, and applied on a piece of pig's bladder. The use of the ranunculus is to destroy the cuticle on which the arsenic does not act.

The arsenicum citrinum is one of the most active preparations of arsenic, and has often produced fatal effects. Ten parts of arsenic are sublimed with one of sulphur; and this preparation was used by Friccius, as well as white arsenic, in intermittents. To this article we may also refer the preparation recommended by Dr. Adair in the Medical Commentaries for the yaws, and other obstinate cutaneous eruptions, viz. one-eighth of a grain of arsenic triturated with sulphur.

M. Febure's remedy consisted of ten grains of arsenic dissolved in a pint of water, with an ounce of the extract of cicuta, three ounces of Goulard's extract, and a drachm of liquid laudanum. With this fluid the cancer is to be Washed every morning. He joined arsenic internally, and directs two grains to be dissolved in a pint of water, to which must be added syrup of chicory, with rhubarb, half an ounce. A table spoonful is to be given morning and night with half a drachm of syrup of poppies. It may be remarked, that the dose of the arsenic in this preparation is one-twelfth of a grain.

The aqua arsenici is a deliquescing solution of the arsenicum fixum, formed by deflagrating the metal with nitre. This last preparation was recommended by Muller; and, disguised with the wood of red sanders and the terra sigillata, was used by quacks in Germany, and found highly deleterious. The solution is recommended by Hartmann, in a cancer of the nose.

The liquor arsenici albi is formed by deflagrating two parts of nitre, as much arsenic, and sometimes one part of sulphur. This also has been recommended in cancers; while a solution of arsenic in the muriatic acid, the butyrum arsenici, is only employed as a caustic.

It is unnecessary to follow the use of orpiment, the arsenic of the Greeks, the Romans, and Arabians, through the numerous authors who have spoken of it, and who have used it in a variety of diseases, assisted or directed by the medicines peculiarly adapted to them. In fact, the additional remedies were successful, for little was obtained from the metal, especially if loaded with sulphur.

Arsenic is, however, a valuable internal remedy in its appropriate dose, viz. about one-eighteenth part of a grain. We have often mentioned the tonic power of metals, and amongst these have instanced arsenic. We fine; a strong proof of this power when given to horses. From ten grains to half a dram given daily will bring a horse into excellent condition, render him healthy and active, improve his appetite and the gloss of his coat. It was not, however, by such observations that quacks and mountebanks were first led to employ it. The practice was earlier than the commencement of the last century, for it is mentioned by some of the earliest authors of that era. It was not, however, exhibited alone, but with a variety of other medicines which were supposed to correct its virulence. Among these the mountain crystal, crystalline quartz, was thought most effectual in destroying its virulence; but pepper, crabs' claws, and vinegar, were also added. Fourcroy mentions its being repeatedly boiled with crystals of tartar, and afterwards crystallized; Dr. Willan and Dr. Fowler boil it with salt of tartar, Monro with pearl ashes, and Gmelin with antimonial nitre. The salt of tartar, supposed to form the arsenicated potash, we suspect does not unite with the arsenical acid; for Caels, in the Brussels Memoirs, vol. iv. found it equally fatal to rabbits, cats, and dogs; nor do we find that the stomach will bear a larger dose of this supposed metallic neutral, than of the arsenic uncombined. Macquer combines the metallic acid more effectually with potash, by melting and subliming them together.

The use of arsenic as an internal remedy for intermittents was first known, in consequence of the credit Edward's ague tincture obtained for their cure. This was said to be a saturated solution of the arsenic in water; but it cannot be true, as the dose then would be little less than an eighth of a grain; on the contrary, it is less than what is usually given. We used Edward's ague tincture, in 1780, in some obstinate intermittents brought from Coxheath camp, with complete success; and imitated it very soon afterwards by a solution of arsenic in common water. We can truly add, that from very long and frequent experience we never found the slightest reason to suspect it of any bad effects. We are certain that neither dropsy nor hectic was its consequence.

Dr. Fowler recommends it in intermittent pains in the head: for these the bark is often an insufficient remedy. We were led to employ it from finding it the basis of an old woman's remedy, but have not had sufficient experience of its efficacy to speak of it decisively. There are several instances in the Medical Commentaries of its utility in epilepsy.

The plasters which have arsenic for their principal ingredient are numerous: Angelus Sala has given a recipe for an emplastrum magneticum in peste; Crollius, an emplastrum ex magnete arsenicali; and the Wirtem-burg college, in their Pharmacopoeia in 1763, an emplastrum magneticum arsenicale. These were chiefly employed to bring pestilential buboes to suppuration; in obstinate putrid ulcers; as a remedy for cancers; incarcerated herniae, and prolapsed uterus; or to cure obstinate quartans when laid on the region of the spleen. In these instances they are said to have been successful, butfeldman has recorded some fatal consequences from their application.

Arsenicum flavum. Arsenicon. Citirinum, vcl Croceum. See Auripigmentum.

Arsenicum rubrum factitium. See Realgar.

While arsenic, sublimed with one-tenth its weight of sulphur, is yellow; and with one-fifth it is red.

Both the yellow and the red fossil arsenics, when of a smooth texture, are called zarnichs; but when composed of small scales or leaves, they are called auripig-menta.