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bichloride, united with a small quantity of opium. administered, in the commencement, four a day, half an hour after the dinner meal. Twelve grains of the bichloride are made with an inert powder, as liquorice, into 238 pills. Four of these pills are given the first day; the day but one after, six; increasing the dose two pills every day, and leaving one day's interval between each dose, so that, on the thirtieth day from the commencement, the patient takes thirty pills, or one grain and a half of the salt.

The bichloride of mercury is much better administered in solution. I so exhibit it, with some decoction of the woods, either of guaiacum or sarsaparilla. From twenty drops to

a drachm or more of the liquor hydrargyri bichloridi may be given in a tumblerful of one of these decoctions, twice or thrice a day, with the best effect. United with bark and hydrochloric acid, it is also exceedingly useful in the advanced stages of constitutional syphilis in debilitated habits.

Mixed with lime-water, in the proportions of from four to eight grains to the half-pint, it forms a useful application to inany secondary venereal ulcers. I exclude from consideration the method of Cirillo, which consists in using the bichloride mixed with lard, by way of friction, on the soles of the feet. By Continental surgeons, the bichloride is used to produce the ordinary effects of mercury in primary syphilis, to which, in my opinion, it is little suited.

THE IODIDE OF MERCURY.

The iodide and biniodide of mercury were first introduced into the therapeutics of syphilis by Biett of St Louis, and since largely employed in that hospital by his successor, M. Cazenave. They are most valuable remedies in the treatment of many forms of constitutional syphilis, and I have for years employed them both, but more especially the biniodide, with almost uniform success. Many surgeons who have employed it associate it with opium; but Biett and Cazenave state that its combination with opium destroys its curative properties, although its efficacy is increased by treating the patient with daily doses of opium for a few days before the use of the iodide

is commenced; it is useful also to omit the remedy for a day, every three, and give a full dose of opium. The iodide of mercury must be administered in the form of a pill combined with lactucarium, in doses of from one to three grains.

B Hydr. iodidi, gr. x ;

Lactucarii, ij. M. ft. pil. xx.

From one to four pills a day (Cazenave). A very good way of administering the iodide has been suggested by Dr Neligan, to substitute it for the calomel in Plummer's pill.

B Hydr. iodidi,

Antim. oxysulphuret., āā Zij;
Guaicaci in pulv.,

Sacchari fæcis, āā 3iv. M.

The iodide of mercury is indicated in pustular and tubercular diseases of the skin, in diseases of the bones and testes; in secondary venereal ulcerations, where the constitution has long suffered protracted and varied treatments, and still the disease remains. It frequently cures after the failure of other remedies; its employ should be associated with a nourishing, but not stimulating diet, decoctions of the woods, and the mercurial vapour bath. The iodide is an uncertain remedy, producing commonly griping pains, in however small a dose it may be given. M. Ricord employs it by giving one grain every evening, after the last meal. When the dose is to be increased, one is to be taken in the morning, and one in the evening. It is chiefly indicated in constitutional, not in primary syphilis.

THE BINIODIDE OF MERCURY.

I prefer the biniodide of mercury to the iodide; I find it agree well with the gastric condition of the patient, which the iodide frequently does not. It is more manageable, and can be given in solution, a great advantage. I employ it in solution with the iodide of potassium, a combination which I have been in the habit of prescribing in the Queen's Hospital for years.

B Hydr. bionididi, gr. iij;
Potass. iodidi, Zj-iij;
Sp. vini, j;

Syrup. zinzib., Ziij ;
Aquæ dest., 3jss. M.

Twenty or thirty drops three times a day, in half a tumbler of some decoction of the woods. M. Puch, of the Hôpital du Midi, employs a form somewhat similar. This remedy is indicated in the same cases as the iodide. Used in small doses, with the mercurial vapour bath, it produces excellent cures.

THE BICYANIDE OF MERCURY.

The bicyanide of mercury is frequently employed in secondary syphilis, and for the following reasons:-It is soluble and not liable to decomposition, acts quickly, and does not occasion those pains in the stomach and bowels that so frequently accompany the prolonged administration of some other preparations. According to the researches of M. Parent-du-Châtelet,1 the bicyanide of mercury is not decomposed by either acids or alkalies, nor by decoctions containing azotized principles or gallic acid.

The bicyanide of mercury may be administered internally in pills, or in solution, and used externally in form of pomade or ointment. Externally, it is an extremely useful application to various forms of herpes, particularly that form termed by Alibert "herpes squamosus," the violent itching and irritation of which it allays. It may be employed externally also as a dressing to indolent syphilitic ulcers and schirrous tubercles, or as a gargle in ulcerations of the throat. The dose of the bicyanide is from one-sixteenth of a grain to a grain.

Half an ounce for a dose, administered in a sudorific decoction of the woods, night and morning.

PILLS OF THE BICYANIDE OF MERCURY.

R Hydrargyri bicyanidi, gr. xxiv;
Ammonia hydrochloratis, 5iij;
Guaiaci gummi, 3iij;
Ext. aconiti, 3iij;

Ol. anisi, mxxiv.

M. mucilaginis, q. s. ft. pil. 400.

One or two twice or three times a day, the dose gradually increased. Each pill contains about one-sixteenth of a grain of the bicyanide. These pills are a substitute for the bichloride of mercury in many forms of secondary syphilis. M. Desmartis, of Bordeaux, says that the cyanuret (bicyanide) of mercury is superior to all the other preparations of this metal in the cure of constitutional syphilis. He has seen it restore to health patients whose cases seemed hopeless. He has found it efficacious in cases where the patients had suffered for long periods from pains, for which no cause could be discovered. It is indicated in syphilitic diseases of the nose and fauces. I have had some experience in the use of the bicyanide. It does not purge or gripe. A patient requested me to prescribe for him a mercurial that would not purge him; he had a scaly eruption always benefited by mercury, but he could not continue the remedy long enough to cure him, as it always produced diarrhoea in any form that he had hitherto taken it. I prescribed the bicyanide, under the use of which the eruption disappeared without the usual ill effects accompanying the administration of the other preparations of mercury.

THE IODIDE OF POTASSIUM.

Iodine and its preparations, more particularly the iodide of potassium, are employed largely in the treatment of all forins of syphilis. Desruelles has recorded several cases of the cure of primary sores with the iodide. Hanck and Kluge have, on the contrary, given the results of four hundred cases of primary syphilis in which the iodide of potassium had little or no

effect. M. Payan has related some cases of indurated chancre, and primary sores with bubo, which yielded to treatment by the iodide. My own experience is against the use of the iodide in primary syphilis, except in some cases of phagedena, in bad habits of body, where I have seen it useful. M. Payan lays it down as a principle, that the efficacy of the iodide of potassium is in direct ratio with the long standing of disease; and hence many surgeons have been led to regard this remedy as almost specific in tertiary symptoms, such as nodes, tubercles, affections of the testes, pains in the bones, caries, and certain forms of secondary ulcerations. M. Ricord regards the iodide of potassium as a prophylactic against tertiary symptoms, when secondary symptoms have disappeared under the use of mercury.

It is certainly in the class of cases just alluded to that the iodide of potassium is most useful, and under many circumstances works remarkable cures. The iodide of potassium, as I have already said, is not to be depended on in the treatment of primary sores; neither is it generally indicated in the earlier stages of secondary eruptions in healthy subjects, nor in the confirmed or chronic stages of scaly or papular diseases of the skin. In such complaints, antimonials, or the bichloride or biniodide of mercury in small doses, in decoctions of the woods, are infinitely more certain and effectual.

In pustular and tubercular skin disease, or in the secondary forms of ulceration which succeed to these, more especially if mercury have failed in their treatment, or the patient be weak and debilitated, or over forty years of age, the iodide of potassium is a most valuable therapeutic agent.

There are, however, many cases of this nature in which the iodide rather suspends than cures disease; and its prolonged use disposes to wasting of the body, and under some circumstances utterly destroys the digestive powers. I have known cases where it has been taken respectively for three, five, nine, and ten years; and in these cases the symptoms have returned when the iodide has been discontinued. A case will be found in the next chapter, of a surgeon, who took three daily doses for ten years, and yet his disease remained. Whilst he took the iodide, the symptoms were kept under; but when he omitted it, they always returned. Pains in the bones are very apt to