The various neuroses occasionally assume the same regularity of recurrence. Epileptic convulsions, in general so intractable, may be treated with quinia with good hope of success, when they occur regularly, for any length of time, at the same hour daily, or every other day.

The same may be said of hysteria. Cramps, internal spasmodic affections, asthma, nervous cough, and amaurosis, are other complaints occasionally periodical in their character, and, in that state, curable by the great antiperiodic remedy.

Hemorrhages are said also to be sometimes regularly intermittent, and remediable in the same way.

The fact is undoubtedly true of certain complaints of an apparently inflammatory character. Among these, ophthalmia is mentioned; but, considering the frequency of neuralgia of the eye, I am disposed to think that these cases of apparent inflammation are little more than active congestion, sustained by the extreme nervous irritation, and subsiding when that ceases. I have repeatedly seen diarrhoea periodical, and in that condition yielding to quinia; but it is not always easy to determine whether the affection is inflammatory, or merely irritative. One of the most apparently violent attacks of dysentery which I ever saw proved to be regularly periodical. The case occurred in the Pennsylvania Hospital. At my first visit, the man was seemingly very ill, complained excessively of pain, was constantly going to stool with the characteristic dysenteric discharges, and seemed to me to be in great danger of his life. Next day he was almost well; and I supposed that the disease had yielded to the measures employed. On the following day, however, it returned with all its former violence, and subsided again as before. There were several similar paroxysms. Convinced that it was periodical, I gave sulphate of quinia very largely in the intermission, and almost immediately checked the disease. But the probability, I think, is that, in all these regularly intermittent inflammations, the nervous element of the disease is predominant, and that the vascular disturbance is directly dependent upon it. In many cases, however, of apparent intermittent inflammation, especially of the lungs, the local affection is a mere appendage of a miasmatic fever, being lighted up by the general vascular excitement of the paroxysm, acting probably upon a predisposition to inflammation in the organ affected. But, whether its origin be as here supposed or not, it yields with great facility to quinia, when there is proof that the inflammation is quite absent during the period of the apparent intermission.

In regular remittent diseases, quinia is scarcely less efficient than in intermittents. In this category, however, are not included all affections having the remittent character. In consequence of the varying excitability of the system, almost all complaints, perhaps it may be said all complaints of any considerable duration, are more or less remittent, even though the cause may be constantly operating. But to constitute a regular remittent, in the sense here intended, there must be a paroxysm recurring daily, or every other day, at regular intervals; and, though the morbid action may continue, in a moderated degree, throughout the intervening period, yet it is rather a prolongation of the paroxysm, than a continuous and sustained effect of the cause. It is as if the cause operated only paroxysmally, and the disturbance of system produced by it did not subside completely before the period arrived for the recurrence of its action. These diseases, then, are not continuous affections, undergoing occasional exacerbation and remission; but consist of successive paroxysms, more or less intercurrent They are closely analogous to intermittent disease, and are submissive to the same antiperiodic treatment.

The most important of these diseases is the miasmatic remittent, or common bilious fever. In this complaint, sulphate of quinia is a most efficient remedy. Whenever a decided remission is observed, after due evacuation of the bowels, and of the stomach if necessary, it may be given in quantities similar to those administered in intermittent fever, and will not often fail. In the pernicious variety of remittent fever, or when pernicious symptoms supervene in a case before simple, it is all-important, and, indeed, is the only remedy on which reliance can be placed. As in the pernicious intermittent, the quantity should be double, or even triple that given in the milder form of the disease. In this affection, it is of vast importance that no time should be lost. The next paroxysm may very possibly prove fatal, unless prevented. Nothing, therefore, should be allowed to interfere with the use of sulphate of quinia, upon the first occurrence of signs of remission; and sometimes it might be advisable not to wait for this period, but, when the nature of the disease is well ascertained, to have recourse to the antiperiodic, by anticipation, even in the paroxysm; for the tendency here is not to active congestion or inflammation, but rather to nervous prostration and passive congestion, and there is little probability of serious injury to the brain, or other vital organ. In some instances, it is difficult to retain the remedy, on account of great irritability of stomach. It should not be omitted on this account, but given notwithstanding, in the hope that a portion at least may be retained; and its retention may be aided by the simultaneous administration of opiates, and by the application of a sinapism to the epigastrium. The remedy should also, under such circumstances, be additionally employed as an enema with opium, and as an application to the surface of the body by the endermic method; or, what is still better, by injection into the subcutaneous areolar tissue.

In regular remittent neuralgia, also, the best effects may be expected from sulphate of quinia, given in the same manner as in the intermittent form of the disease.