The intermitting nature of this complaint is known rom its occurring in the low, damp, marshy situations, from its regular recurrence, and from the remedies which relieve it. But among these we cannot reckon the Peruvian bark alone; for, though large doses have sometimes appeared to cure, they arc often ineffectual, so that we are rather inclined to attribute the relief, sometimes experienced, to the spontaneous cessation of the disease. The remedy which most frequently succeeds is that recommended by Dr. Grant, consisting of an ounce of valerian, half an ounce of bark, two drachms of the Philonium Londinense, one drachm of kali, with a scruple of rhubarb, made into an electuary with simple syrup. He remarks, what we have found to be true, that it this quantity is swallowed between two paroxysms, the last will be greatly mitigated; and if the same quantity-is swallowed between the two next, the complaint will be so far cured as to be scarcely troublesome. The effects of this plan, however, are rendered more certain by gi\ ing an emetic before the expected attack, with a blister behind the ear of the side affected; and as it is necessary to keep the bowels free, which the proportion of rhubarb is unequal to, the period of the accession may be employed for this purpose. The duration of the pain is amply sufficient for the operation of salts, of the oleum ricini, or- jalap.

The quantity to be taken, according to this plan, may be sometimes inconvenient; but the pain is so excruciating that we have scarcely found any one whose resolution has not been equal to the alternative. It sometimes, however, though rarely, has happened, that the stomach will not retain it: the resolution has occasionally failed; and even the medicine has not succeeded, for the disease in our practice has been frequent. In such circumstances the copper has sometimes relieved; and, in more than one instance, a secret medicine, which is pretty certainly a solution of arsenic. If the period of the fever is not required for the action of a laxative, the pain may be mitigated by opium, with which camphor or musk has been combined; but of these additions we cannot speak from our own experience.

Other periodical pains and nervous complaints, as the hooping cough, hiccough, nausea, colic, and palpitations, regularly recurring, are very frequently removed by the same means (Senac). It has been usual to give the bark in every periodical complaint; but it seldom succeeds, except in doses much more inconvenient than those of Dr. Grant's medicine; and, when it seems to relieve, it leaves the patient more subject to relapse.

There are, however, symptoms periodically recurring, not always of. this kind; but we have only been able to trace them when belonging to one disease, viz. lues venerea. We have seen a periodic ophthalmia, a haemicrania, and an haemorrhage from the nose, recurring at regular intervals in this disease. Each has been cured by a mercurial course. It may be said, that mercury, like copper and arsenic, will remove it; and it may be true, but each laboured under syphilis. The patients are at this moment alive, and the author, by a personal application, has refreshed his memory on the different subjects. We must add, however, that Senac, an author of the highest credit, mentions intermitting haemorrhages, ophthalmy, ear and toothach, cephalalgia, pains under the scapula, nephritic affections, pain of either leg or arm, and of the stomach, often, without any other appearance of fever. Those inter-mittents also which we have mentioned as attacking with syncope, apoplexy, asthma, and convulsions may

5 N 2 be properly styled larvalae. The nature of these cannot be at once known; but some opinion may be formed from the prevailing epidemic, from the damp marshy situation in which the patient lives, from the bilious vomiting, the lateritious sediment in the urine, from the recurrence; but, above all, as we have said, from the very perfect intermission. The third paroxysm is popularly supposed to be fatal; indeed it often is so.

The varieties of intermittents which we have noticed, in which the cold obstinately continues; where the hot fit becomes phrenitis, or where the subsequent debility is attended with marks of putrefaction, and the worst symptoms of malignant fevers, have been reckoned among the disguised intermittents by Morton and Torti. But these authors were preceded in this opinion by Salius Diversus, by Valesius, Mercatus, etc. Indeed were a descriptive (raisonne) Medical Biography, a work much wanted, ever published, numerous reputed discoveries might be carried far beyond the ages of the supposed authors.

We have already mentioned the manner in which intermittents pass into remittents, and into continued fevers of the worst kind; but we have referred the consideration of these subjects to the Remittents, q. v. which afford examples of the most destructive exacerbating fevers. See Morton de Febribur, Senac de Re-condita Februm Natura, lib. 2.