the tendency to recovery under treatment, the enlargement of the spleen, the presence of hematozoa in the blood.

How are typhoid fever and malarial fever to be differentiated? Typical cases of intermittent and remittent fever are not likely to be confounded with typhoid fever, but if an intermittent or remittent has existed for some time, uninfluenced by medication, a typhoid condition develops, and the symptoms may occasion some doubt in diagnosis. Under such circumstances, the previous history must be considered.

The diarrhea, the rose-spots, the temperature-course of typhoid fever are all different from what is seen in malarial fevers.

The reaction of the urine to sulphanilic acid and sodium nitrite, described by Ehrlich, and a characteristic bacillus are not found in malaria. The detection of the plasmodia of malaria in the blood dissipates even the remotest doubt.

Malarial fever and typhoid fever may coëxist as so-called typho-malarial fever.

How does syphilitic fever differ from malarial fever?

When secondary syphilis is marked by fever, the elevation of temperature usually occurs at night and is associated with bonepains, cutaneous eruption and other evidences of syphilis. Cerebral and meningeal syphilis may also give rise to febrile movement. In many cases, the discovery of the plasmodia in the blood and the results of treatment by quinine on the one hand, and the results of treatment by mercury and iodides on the other hand, must make the diagnosis.

Yellow Fever.

What are the characteristics of yellow fever?

Yellow fever is a specific, epidemic disease of hot climates, occurring in a single paroxysm of three stages: the first, a febrile stage, lasting from thirty-six to forty-eight hours, which sets in with a chill, followed by fever, with capillary congestion, especially of the face and eyes, pains in the head, the back and the calves of the legs, restlessness and anxiety, irritability of the stomach, vomiting, thirst, constipation; the second, a stage of

remission or lull, of less than six hours, in which the fever subsides and the skin assumes a deep-yellow or bronze hue; the third, a stage of renewal, in which the symptoms reappear, prostration becomes pronounced and hemorrhages take place from various mucous surfaces; the vomited matters present a characteristic black appearance. The urine usually contains albumin and often casts. Suppression of urine may occur.

The mind is usually clear almost up to the moment of death, but in some cases delirium and stupor develop.

Death may result from collapse or with convulsions and the symptoms of uremia. If recovery take place, convalescence is often gradual, and may occasionally be interrupted by relapse. Some cases are quite mild, recovery taking place at the end of the first stage. Even grave cases may be so mild in the first stage as to be unrecognized; the patient walking about, to be suddenly seized with prostration, quickly followed by black vomit and death.

An attack protects against subsequent infection.

What are the distinguishing features between yellow fever and malarial remittent fever with jaundice?

Yellow fever is epidemic; remittent fever, endemic. Yellow fever is a disease of a single paroxysm, not lasting more than a week; remittent fever is a disease of repeated paroxysms, of periodic recurrence, and lasts more than a week.

In yellow fever, the eyes become injected and watery, the expression anxious or fierce. In remittent fever, there is no especial change in the eyes or in the expression.

Prostration and muscular pains are decided in yellow fever and are not so prominent in malarial fever.

Delirium is common in bilious remittent fever, and the mind is always dull. Delirium is not common in yellow fever, and the mind is usually clear.

The pulse may become very slow in yellow fever; it is always quick in remittent fever.

Hemorrhages from mucous surfaces take place in yellow fever; not in ordinary remittent fever.

The urine of yellow fever contains albumin, and suppression

may take place; the urine of remittent fever contains no albumin and suppression does not commonly occur. Bile-pigment gradually disappears from the urine of yellow fever and increases in the urine of bilious remittent fever.

An attack of yellow fever confers immunity from subsequent inflexion; one attack of remittent fever predisposes to other attacks. Yellow fever is commonly fatal, remittent fever rarely fatal.

The treatment of yellow fever is uncertain; remittent fever yields to quinine.

Plasmodia malariæ are never found in the blood in yellow fever; they are diagnostic of malarial fever.

How are hemorrhagic malarial fever and yellow fever to be differentiated?

Both hemorrhagic malarial fever and yellow fever occur in hot climates and are attended with jaundice, hematemesis and other hemorrhages.

Yellow fever, however, is epidemic; hemorrhagic malarial fever, endemic. The former consists of but a single paroxysm, of three stages, including a remission; the latter is marked by a series of paroxysms, each followed by a remission.

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Black vomit is the more characteristic of yellow fever; hemorrhage from the kidneys, of hemorrhagic malarial fever. bumin and casts are commonly found in the urine in yellow fever; not in malarial fever. An attack of yellow fever confers immunity from subsequent infection; an attack of malarial fever predisposes to the occurrence of other attacks. The detection of the plasmodia of malaria in the blood establishes the diagnosis.

How is yellow fever to be distinguished from acute yellow atrophy of the liver?

Yellow fever is epidemic; acute yellow atrophy is sporadic. In acute yellow atrophy, the area of hepatic dulness becomes rapidly and decidedly diminished; in yellow fever, there is either enlargement or no demonstrable change.

Yellow fever is, and acute yellow atrophy is not, attended with

a distinct remission in the severity of the attack. Yellow fever is sometimes followed by recovery; acute yellow atrophy is not.

The injection of the eyes, the pains in the back and extremities, found in yellow fever, are wanting in acute yellow atrophy of the liver.

In acute yellow atrophy, leucin and tyrosin are found in the urine, and while cerebral symptoms are more pronounced than in yellow fever, the temperature never rises so high and may even be subnormal.

Weil's Disease.

What are the symptoms of Weil's disease?

Weil's disease, also called acute infective jaundice, is an intermittent febrile affection, usually exhibiting two periods of activity separated by an uncertain interval; the first of a little more, the second of a little less, than a week's duration. The disease may set in abruptly with nausea and vomiting. The temperature at once rises to a considerable height, but falls decidedly on about the night of the fifth day; subsequently declining gradually until the normal level is reached. After an afebrile period of from twenty-four hours to a week, there is a return of fever lasting a few days or a week.

The attack is characterized by headache, vertigo, malaise, debility, somnolence, and, sometimes, nocturnal fever and restlessness, hyperesthesia, diarrhea, muscular pains and jaundice. The pulse is small and frequent and sometimes dicrotic. The respiration is accelerated. The areas of splenic and hepatic percussion-dulness are increased. The urine passed is diminished in quantity and contains bile-pigment, bile-acids, albumin and casts. Hemorrhages from various mucous surfaces may take place, epistaxis, hematemesis, hemoptysis and intestinal hemorrhage. Petechial spots may appear in the skin.

The disease has been observed most commonly in summer and in vigorous young men, butchers and soldiers seeming to display a peculiar proclivity. Similar manifestations have followed poisoned wounds. In fatal cases, degeneration of the

liver and kidneys and spleen has been found. Parotiditis, pneumonia, iridocyclitis and motor weakness have been sequelae. In cases that recover, the convalescence is protracted.

How are Weil's disease and yellow fever to be differentiated? Weil's disease and yellow fever probably exhibit a closer resemblance in description than in actuality.

Weil's disease shows a special predisposition for young adults, especially butchers and soldiers; yellow fever occurs in epidemics and does not confine itself to any class of individuals. Diarrhea is the rule in Weil's disease; constipation in yellow fever. The initial stage of yellow fever is of shorter duration; it is earlier attended with a remission; the remission is less complete, and both the remission and final stage are shorter than is the case in Weil's disease. Black vomit is not common in Weil's disease; the injection and excitement are less than in yellow fever.

The Exanthemata.

What are the exanthemata?

The term exanthemata or eruptive fevers is applied to a group of contagious, epidemic diseases, each depending upon a specific infection and having as prominent signs, fever and specifically characteristic eruptions on the skin and often on the visible mucous membranes. As exanthemata are commonly described scarlatina or scarlet fever; measles or morbilli; French measles or Rötheln; smallpox or variola and its modification varioloid; vaccinia--the usual consequence of vaccination; chicken-pox or varicella. Diphtheria and erysipelas might also be included.

Morbilli-Measles.

Upon what does the diagnosis of morbilli depend?

Morbilli or measles, also called rubeola, is an acute, contagious disease, common in children, attended with catarrhal symptoms (coryza, rhinitis, pharyngitis, laryngitis, bronchitis, conjuncti