In cases that recover the temperature gradually subsides at the end of the second week, a decided decline taking place on the fourteenth or sixteenth day, accompanied, perhaps, with profuse perspiration, diarrhea or a copious discharge of urine. Relapses are rare. An attack confers subsequent immunity. Pulmonary complications are the most common. Others may be meningitis, phlebitis, gangrene, erysipelas, parotiditis, edema of the larynx. During the last stages, or after convalescence, acute tuberculosis may develop.

How are typhoid fever and typhus fever to be differentiated? Typhus fever is contagious; typhoid is not. Typhus is the more likely to be epidemic. Prodromata are more common and of longer duration in typhoid. The onset is acute in typhus, insidious in typhoid. Typhus lasts about two weeks; typhoid not less than three. The eruption of typhoid consists of small rose-spots, usually confined to the abdomen and chest, and appearing in successive crops; that of typhus is coarse, macular and petechial and of more extensive distribution. The skin is

usually moist in typhoid; it is dry in typhus. In typhus, the body exhales a characteristic musty odor. The bowels are often loose in typhoid fever; they are usually constipated in typhus. Nervous prostration is the more profound in typhus. The course of the temperature is different in each. Epistaxis is common in typhoid; uncommon in typhus. In typhoid fever, one finds on post-mortem examination intestinal ulceration and enlargement of the spleen and of the mesenteric glands; in typhus, no constant lesions; though the spleen is likely to be diffluent. Typhoid fever and typhus fever may, though rarely, coëxist in the same patient.

How are variola and typhus fever to be differentiated?

Both variola and typhus fever are in a high degree contagious. Should both be simultaneously epidemic, the diagnosis may be difficult during the first few days of the attack. The eruption of variola, however, appears from twenty-four to thirty-six hours earlier than that of typhus. The former is usually situated on the face, as well as on the trunk, and passes successively through the stages of papule, vesicle and pustule, the pustules

rupturing and leaving cicatrices. The eruptionof typhus fever rarely or never appears on the face; it remains largely papular, though in part it becomes petechial. In typhus fever, the temperature becomes high at the onset and continues high; in variola, the temperature declines with the appearance of the eruption. Vaccination commonly protects against variola; it affords no protection from typhus fever. Finally, typhus is a disease of about two weeks' duration; variola, of quite three.

Cerebro-spinal Fever-Epidemic Cerebro-spinal Meningitis.

What are the clinical features of cerebro-spinal fever? Cerebro-spinal fever or epidemic cerebro-spinal meningitis-a specific, essential fever of continued type, associated with a constant lesion-is an acute and extremely fatal infectious disease, varying much in its clinical manifestations, but usually characterized by decided disturbances of the cerebro-spinal functions. In some cases cerebral, in others spinal symptoms predominate. Not infrequently, respiratory phenomena or bloodchanges assume great prominence. A characteristic eruption is usually a marked feature.

The attack may develop gradually, but more often it sets in suddenly, with a rigor followed by fever; malaise; nausea; great thirst and vomiting, often with a clean tongue and no gastric derangement; vertigo; excruciating headache, remitting, but never entirely ceasing, and attended with paroxysmal exacerbations; rigidity of the head and neck, sometimes passing into opisthotonos; muscular twitchings or convulsions; dryness of the skin, with hyperesthesia and paresthesia. There may also be photophobia and tinnitus aurium. Prostration soon becomes profound, though restlessness may continue. Delirium may set in and be followed by stupor and coma. The expression is anxious. The pulse is rapid and extremely irregular. The temperature fluctuates between wide limits. Hyperpyrexia is not rare. It may develop suddenly and persist until death. The temperature may continue to rise after death. A

sudden fall of temperature may usher in collapse and death. A gradual fall of temperature precedes recovery. The action of the sphincters is often deranged, so that there may be incontinence of urine or feces, or retention of urine, or constipation. As a rule, retention is an early, incontinence a late symptom. The urine is often albuminous and contains an excess of urates. Between the first and the third day, purpuric spots, or an erythematous eruption that quickly becomes petechial, may appear upon the trunk and extremities. The disease is sometimes called "spotted fever," from the character of this eruption. Between the third and the sixth day, herpetic vesicles may appear on the face about the lips.

In the further progress of the case, the pupils, at first contracted, become dilated; paralysis and anesthesia of irregular distribution appear; disturbances of sight and hearing, perhaps also blindness and deafness develop. The respiration may be profoundly disturbed. As death approaches, the breathing may assume the Cheyne-Stokes type. Short remissions in the general severity or in individual symptoms may occur, to be followed by renewed exacerbations. The duration of the disease is variable. The fastigium is commonly reached on the sixth day. In protracted cases, profound emaciation occurs. Death may take place early or late, in coma, by exhaustion, or by apnea. If recovery ensues, convalescence is tardy, and sometimes protracted, while permanent loss of special senses is common. Pneumonia

is a common complication. Palsies, headache and epileptiform convulsions may be additional sequelæ.

In addition to the ordinary type of epidemic cerebro-spinal meningitis, there may be fulminant cases (death occurring within twelve hours), mild or abortive cases and protracted or typhoid cases. Sporadic cases are rare.

Instances of contagion (direct transference from the sick to the well) and of portagion (conveyance by the person or belongings of those that have been in contact with the sick) of cerebro-spinal fever appear to have been authenticated, but are extremely uncommon.

How are cerebro-spinal fever and tetanus to be differentiated? Cerebro-spinal fever appears in epidemics, while tetanus usually occurs sporadically, as a result of the infection of a wound by soil. Trismus, an early symptom of tetanus, is the less common in cerebro-spinal fever. Opisthotonos, general rigidity and spasm are more marked in tetanus than in cerebro-spinal fever. Recovery from tetanus is exceptional. Death is not the invariable termination of cerebro-spinal fever.

Tetanus is wanting in the palsies, the eruption, the derangement of intellection and sensation and the febrile symptoms of cerebro-spinal fever, though towards the fatal termination the temperature may rise inordinately high.

How are cerebro-spinal fever and typhus fever to be differentiated?

While both cerebro-spinal fever and typhus fever occur in epidemics, and both may be sudden in onset and attended with profound nervous phenomena and petechial eruption, cerebrospinal fever has not the dusky, stupid facies of typhus, while the herpes of the face, the retraction of the head, the fixed spinal pain, the muscular rigidity and the heightened sensibility of cerebro-spinal fever are not observed in typhus; nor is typhus, as a rule, accompanied with the great impairment of special senses or followed by the paralytic sequelae of cerebro-spinal fever. The general course of the two diseases, the fever and the eruption may be discriminated on careful observation. The greatest difficulty occurs in cases of malignant cerebral typhus. How are cerebro-spinal fever and torticollis to be differentiated?

The muscular contraction that gives rise to torticollis is usually unilateral and limited, while in cerebro-spinal fever the contraction is symmetrical and not confined to the muscles of the head and neck. The symptoms of an acute, febrile disease, with disturbances of the sensorium and paralytic concomitants and sequelæ, are not present in torticollis, but are characteristic of cerebro-spinal fever. Even mild cases of cerebro-spinal fever, lacking the characteristic febrile course and without eruption, will present severe headache.

What are the distinctions between cerebro-spinal fever and smallpox?

Headache, vertigo, nausea, vomiting, pain in the back and fever attend both cerebro-spinal fever and smallpox; but retraction of the head, muscular rigidity and paralysis, hyperesthesia and anesthesia are wanting in smallpox, and the peculiar temperature-record and the characteristic eruption of smallpox are not seen in cerebro-spinal fever.

What are the distinctions between cerebro-spinal fever and yellow fever?

Yellow fever is especially a disease of hot climates; when found elsewhere its importation may be traced. If cerebro-spinal fever display any susceptibility to climatic conditions, it is most common in temperate zones. Characteristic symptoms of motor and sensory derangement, observed in the course of cerebrospinal fever, are wanting in yellow fever, which is a disease of brief duration, in contrast to cerebro-spinal fever, the duration of which may be protracted. Petechial and herpetic eruptions appear during the progress of cerebro-spinal fever, while yellow fever is characterized by a saffron-yellow color of the skin. The black vomit often seen in yellow fever is entirely wanting in cerebro-spinal fever. Although remissions in the intensity of special symptoms may occur in the course of cerebro-spinal fever, the characteristic "lull" of yellow fever is absent.

How are cerebro-spinal fever and typhoid fever to be differentiated?

In cerebro-spinal fever, the onset is usually abrupt; in typhoid it is insidious. In typhoid fever the temperature pursues a typical course; in cerebro-spinal fever there is no regularity. The eruption of cerebro-spinal fever is petechial or herpetic and appears early-before the fourth day; that of typhoid is roseolous and appears not earlier than the fifth or sixth day. Constipation is the rule in cerebro-spinal fever; diarrhea often attends typhoid. Nausea and vomiting occur in cerebro-spinal fever, but not usually in typhoid. The retraction of the head, the paresthesia and the paralyses of cerebro-spinal fever are all wanting in typhoid fever. The headache is more