INTERMITTENT FEVERS - The great distinction of this class of fevers is their perfect in termission. All fevers are liable to exacerbations ; and the remis sions were considered in former times, no less essential than any of the other symptoms, such as hot skin, quick pulse, &o. They are now regarded rather as accidental, and dependent on extrane ous causes, than as belonging to the necessary effects of the fever itself', when it comes under any of the classes already enumerated. But when complete intermission occurs, and when the patient for a long time feels tolerably well during the interval, the type of fever is wholly different. The history is, therefore, one of the most important guides to diagnosis. If a patient be seen just as the cold stage is passing away and the hot one commencing, during the first paroxysm, or if he have not sufficient intelligence to have marked the succession of its stages in a previous one, there is nothing to distinguish it from simple fever. The cold stage is more marked, and the heat of skin is out of proportion to the duration of the attack, and to the appearance of the tongue ; but this is not sufficient to distinguish it from the incur sion of eruptive fever, or of some inflammation, until profuse perspiration follows and the complete intermission arrives. The absence of the special indications already pointed out, and of local pain, probably contradict such an idea ; and we then inquire into the possible causes of the attack, and especially the exposure to local malaria in ague districts.
The rigor is generally intense, and the perspiration profuse— such, indeed, as are never met with except in deep-seated suppu ration ; and if there be no history of any serious derangement of health, which would of necessity accompany previously existing disease of any internal organ, there need be little doubt of the nature of the case. These symptoms are soon followed by com plete intermission ; and, finally, the recurrence of the attack, after a longer or shorter interval, makes up the entire history of the disease.
The completeness of the intermission, the disappearance of everything like fever in these cases, deserves especial observe. tion ; because it forms the most trustworthy evidence of the true nature of the disease. Delusive hopes, and perhaps mischievous treatment, are not unfrequently based upon intermissions which have an appearance of regularity, but are incomplete in other characters. The intermittents of the tropics do not so invariably
follow this description ; but in this country, except the patient be worn down by oft-repeated paroxysms, I think it extremely dan gerous in diagnosis to admit that any fever belongs to this class, simply because the remissions assume some regularity of type. The paroxysms in ague may recur at nearly the same time next day, when it is called quotidian ; on the third day, tertian ; or on the fourth day, quartan. These are all regular intermittents; and an approach to regularity in the period of recurrence is the rule in the greater number of cases. Occasionally an appearance of irregularity is produced by anticipation or postponement of the paroxysm ; the former in the commencement, the latter in the decline of the disease : the rigor begins half an hour or an hoar earlier or later on each recurrence. Another cause of an appear ance of irregulafity is the existence of what is called double-ter tian : the paroxysms on the first and third day begin at the same hour, but on the second day the rigor comes on at some dilferent period ; and this is again repeated on the fourth day : it thus simulates an irregular quotidian. The curative treatment is now so quick and efficacious in the early period, that opportunities are seldom offered in this country of studying such phenomena.
Sometimes the paroxysms recur at such irregular intervals that the disease must simply be called an irregular intermittent. These cases are rare ; and wIten they supervene on previous dis order, the possibility of deep-seat suppuration must be con sidered and the judgment held in suspense, until their distinct recurrence on one or two occasions, and the condition of compa rative health and freedom from disorder &fling the intermission, relieve the mind from such an apprehension. On the other hand, when serious derangement of health has preceded the first shiver ing, irregular paroxysms are most probably caused by suppura tion ; and when the patient continues ill during the interval4 this probability amounts almost to certainty, even when we cannot make out its exact se-at.