Nor can i, in any degree, coincide in that opinion which ascribes to mercury effects analogous to those of secondary syphilis. Glandular swellings, ulcerations similar to the venereal in the throat, various eruptions on the skin, cutaneous ulceration, periosteal nodes, and rheumatic pains have been attributed to mercury; and, in reading some writers on the subject, one might almost be led to doubt whether secondary syphilis actually existed, and to imagine that what had been mistaken for it was really mercurial disease. it is impossible for me to believe in these supposed effects of mercurials; because, among the thousands to whom I have given the medicine, I have never, in any single instance, seen, as a consequence of it, anything which I could mistake for a venereal affection. it is true that some consider the phenomena referred to as the conjoint effect of mercury and syphilis; the former having called them into operation in persons affected with the latter, when otherwise they might not have appeared. But the source of fallacy is here so obvious, that the strongest proof would be required to establish so strange an hypothesis. A disease exists with a certain train of well-marked and highly characteristic symptoms, which mercury will beyond all controversy occasionally cure. in the healthy system, mercury never produces symptoms which can be mistaken for those of the disease in question. Yet, given to a patient in the early stage of the disease, so far from effecting a cure, it sometimes generates all the subsequent characteristic phenomena, which now take the name of mercurial disease. it seems to me, that only an exceedingly strong prepossession could prevent a well-informed man from seeing anything but absurdity in such a statement.

Much of the false opinion in relation to this imaginary mercurial disease, and much of the failure to cure syphilis, have I believe resulted from a cause already referred to (see page 218); an incautious use, namely, of the medicine, in consequence of which a degree of stomatitis has been induced, which rendered its omission necessary, before there had been time for it to eradicate the disease. The syphilitic symptoms, suppressed for a time, have afterwards returned, and been ascribed to the mercury. if the medicine had been given cautiously, and continued sufficiently long, the disease would have been eradicated, and none of the secondary symptoms would have shown themselves. I once had a case strongly illustrative of this view. The patient had been long affected, and was reduced to the lowest stage of debility, with ulcers, eruptions, etc., which appeared to me obviously of syphilitic origin. I was assured, however, that they were the result of mercury, which had been taken several times, but had always been followed by a return of the symptoms, even in an aggravated form. The patient was extremely susceptible to the influence of mercury, and on each occasion had been severely salivated by a small quantity of the medicine, which was consequently relinquished. I administered the blue mass with extreme caution, and succeeded in producing but a comparatively slight effect on the mouth, which permitted me to persevere with the medicine for a considerable time. As soon as the mercurial impression was felt, the symptoms of the disease began to decline; and the amendment continued to go on progressively till a perfect cure was accomplished. I saw the patient, from time to time, for a long period afterwards, and thus had an opportunity of knowing that the cure was permanent.

c. Febrifuge Action. - Though mercury has frequently been given in fevers, with the simple view of subverting the disease, we have no reason to suppose that it has any special febrifuge virtue. That it is of great use in certain febrile diseases cannot be denied; but it probably operates simply by correcting some unessential condition associated with the fever, accidentally or otherwise, but which may very much aggravate the disease, and prove the cause of a fatal termination if not obviated. Whenever inflammation attends an idiopathic fever, and refuses to yield to such ordinary antiphlogistic measures as may seem to be indicated, mercury should be resorted to; and there are few diseases of this character which do not sometimes offer occasion for the use of the remedy.

In the bilious remittent fever, calomel, carried to full mercurialism, is probably, next to sulphate of quinia, the most efficient remedy in violent or obstinate cases. it is indicated by the congested state of the liver, and the frequently defective secretion of that organ; but the chief ground upon which its employment rests is that of experience; the case seldom terminating unfavourably, when mercurialism has been established. Though now rendered unnecessary, in the vast majority of cases, by the success with which the cinchona alkaloids are employed, yet if these have failed, or from any cause be forbidden, and the case has assumed a threatening character, calomel should be employed with a view to salivation. it may be given in the dose of a grain every two hours till its effects on the mouth are produced, and then diminished or suspended. it is not unfrequently associated with the nitrous powder, when the skin is hot and dry, the pulse strong, and the stomach free from irritation. in the low typhoid state in which the fever sometimes ends, with a dry tongue and scanty secretions generally, I prefer the blue pill, given as will be explained directly in enteric fever.

Yellow fever affords a strong indication for the use of mercury, in the almost perfect torpidity of the liver, which fails to perform its functions, at the very time that its action becomes important in order to depurate the blood. it is highly probable that the absorbed poison acts directly on the circulating fluid, causing a rapid disintegration of the red corpuscles, and a consequent excess of yellow colouring matter, which ought to find an outlet through the liver, and, failing of this, gives to the surface the jaundiced hue so characteristic of yellow fever in its second stage. But in this fever, even more strongly than in the bilious remittent, it claims to be employed on the basis of experience. The observation has frequently been made, and the truth of it generally admitted, that whenever mercurial ptyalism can be fairly induced in yellow fever, the patient recovers. Exceptions to the universality of the rule certainly exist, but it is as certainly true to a very great extent. The opponents of mercury maintain that its success is only apparent; as in the violent and fatal cases it fails to salivate, while those in which it produces the effect would recover without it. All admit that, in the worst cases of yellow fever, it is often impossible to induce ptyalism by any amount of the medicine that can be employed, whether internally or externally. But it by no means follows that, when the sialagogue effect can be established, the cure would take place equally without the aid of the mercurial. The argument may be thus stated. As patients almost always get well who come under the influence of mercury, the medicine certainly cannot be accused of producing any serious mischief. it is impossible to say positively, that the recoveries which take place under it are not ascribable at least in part to its influence. if, therefore, it may possibly do great good, and can do no great harm, why not employ it, especially as it is indicated by the state of the hepatic function ? influenced by these considerations, I have no hesitation in recommending the use of calomel. At the very commencement of the disease, from ten to twenty grains may be given as a cathartic, and followed by one or at most two grains every hour, steadily persevered in until it decidedly affects the mouth, or the symptoms of prostration of the second stage forbid its further use. Beyond this quantity, I do not think it desirable to urge the remedy; as, if the system is susceptible, it will be sufficient to effect the object; while much more of it, without increasing the chances of success in due time, may afterwards, if it remain in the system, add very greatly to the inconveniences of the salivation, should this effect be produced.