one's opinion. In practice, prognosis is often of the greatest importance for the physician's credit, and a hasty conclusion, that turns out wrong, is often remembered against him more than any want of success in treatment.

Treatment. In this we should aim first at the removal of the cause where this is possible; if not, we may succeed in neutralizing its influence. One or other of these methods may suffice to cure all the symptoms and troubles of the patients; but in most cases we are also called upon to deal directly with the symptoms, using remedies that have no influence upon the underlying disease. We must, when doing this, never forget that such symptoms hold a position secondary in importance to that of the disease. which causes them. Lastly, we must in all cases counteract the tendency to death, which may, indeed, be the natural course of the disease, or may arise rather as an accident from some infrequent complication. As an example we may take phthisis, which is due to tubercle, and the tubercle bacillus. The removal of this, when once it has obtained a footing, cannot be directly effected. Its influence can be neutralized by the best hygienic surroundings, by fresh bracing air, and by special climates which enable the body to resist the action of the bacillus. In the meanwhile, there are numerous symptoms-cough, expectoration, pain, sweating, diarrhoeawhich will diminish as the condition of the lung improves, and which can be also controlled by suitable medicines. In addition, serious complications may arise, especially hæmoptysis, or spitting of blood, by which life is directly threatened, and such a death may be averted by proper therapeutical means. Pleuritic effusion is an instance in which we have cough, dyspnoea, pain, and distress due to the presence of liquid in the pleura; the removal of the liquid either by tapping, or by the use of drugs, is followed by relief of all the symptoms. One point it is very necessary to impress upon the student —namely, that diseases are to be treated not by medicines or surgical manipulations and operations alone, but by regulations as to rest or exercise, diet, hygienic surroundings, residence, and other considerations.

Preventive treatment, prophylactic treatment, or prophylaxis will only be occasionally referred to. It largely consists in avoiding the causes, and is almost co-extensive with sanitary science. The word treatment is, in this term, applicable rather to the individual than to the disease.

SPECIFIC INFECTIOUS DISEASES.

Before describing the specific infectious diseases it is desirable to say something of the condition known as pyrexia or fever, which so commonly accompanies these processes, though by no means confined to them, and of contagion, or the process by which they are conveyed from one person to another.

PYREXIA.

The terms fever and pyrexia are not always used in the same sense, pyrexia being sometimes limited to the mere fact that the body temperature is elevated, fever comprehending the rise of temperature, together with all the other bodily disturbances which usually accompany it. As is well known the temperature of the body varies in health between 97.5° and 99° Fahrenheit. It is usual to speak of 98.4° as being the normal temperature, and it is very common to find the thermometer give such a record. But there are daily fluctuations of the normal temperature, according to which it is lowest between 2 A.M. and 7 A.M., gradually rises from 7 A.M. to 1 or 2 in the afternoon, remains at a maximum from that time to 7 or 8 in the evening, and then falls to its minimum after midnight.

Registration of Temperature.-The temperature of the body is taken, for ordinary clinical purposes, by means of the clinical mercurial thermometer, which registers the temperature after it is removed from the body, by a portion of the mercurial column being prevented returning into the bulb of the instrument. It is usually about four inches long, so that it can be carried in the pocket. The bulb of the instrument may be placed in the axilla, the groin, the mouth, or the rectum.

In the two former situations it is necessary to see that there is complete contact of the skin with the bulb, and it must remain there sufficiently long for the surface of the skin to attain the temperature of the body generally: three to five minutes commonly suffice, though a very slight rise may be noticed for some minutes longer if the thermometer is left in. In the mouth the bulb should be placed under the tongue, and the stem must be grasped by the lips: two to three minutes are required. Under certain circumstances the rectum may be employed for taking the temperature; the bulb is introduced for one and a half inches. The result is always to be depended on ;

but it is obviously a method that is not always convenient.

It may be well to bear in mind another way of getting at the body-heat-that is, by passing urine on to the bulb of the thermometer, but its application is rather limited. As a fact, the axilla and the mouth are most frequently employed.

Besides

the ordinary clinical thermometer, there is in use a thermometer, shaped like a very small watch, which is sensitive, but has the disadvantage of not fixing its record and there are surface thermometers, which are useful in special investigations.

In consequence of daily variations both in health and disease, it is desirable to record the temperatures at least twice a day; the best times would be 5 or 6 A.M. and 5 or 6 P.M., so that the lowest and highest temperatures should be observed. Social arrangements do not usually allow of this in slight cases of illness, and 10 A.M. and 6 to 9 P.M. are more often the times selected; but it must be remembered that at 10 A.M. the temperature is already rising, and that after 7 P.M. the maximum is generally passed. severe illnesses, like typhoid fever, pneumonia, etc., it is very desirable to take the temperature at least every four hours, when the daily variations can be more closely watched. The temperature should in all cases be recorded on a chart, with a dot for each observation and lines drawn from dot to dot; by this means the oscillations of the temperature are graphically represented, and its general behavior is more closely brought to the mind than by long columns of figures. It has been objected that we can never know what takes place between each observation, and that a line drawn, say, from a dot at 99° to another dot at 101° four hours later, gives a false impression of a steady rise, of which we have no evidence. But when once we recognize that there may have been variations in the interval, we need not be misled by the chart, any more than by a column of figures recording the same observations, and it is certain that the chart gives at once a comprehensive grasp of the course of the fever so far as it can be known from the observations taken. When studying the four-hour chart of a long illness, I have often found it useful to draw up from it a fresh chart, selecting only the lowest morning and the highest evening temperatures, and thus showing, in the most prominent way, the extreme oscillation in the body-heat on each day.

Range of Temperature.-In disease the temperature ranges from 92.3°, or even lower, to 110° or 111°. Temperatures of 116° and 122° have been recorded, but considerable doubt attaches to their genuineness.

Many terms have been used to denote the different degrees of temperature above or below normal; Wunderlich gives eleven in all. But I think the following are all that are practically wanted:

Slight or moderate pyrexia from 99° to 101° in the morning, or 102.5° in the evening. from 101° to 103° in the morning, or 105° in the evening. above 105°.

Severe pyrexia.
Hyperpyrexia,

CONDITIONS ASSOCIATED WITH PYREXIA.

Pyrexia, fever, or febrile reaction, is accompanied by many other disturbances besides elevation of temperature; indeed, every function of the body is more or less upset whenever the temperature is raised for more than a very short time; and the symptoms which will be here shortly enumerated, are present more or less in all the febrile diseases.

Skin. It is hot to the touch, sometimes intensely so generally dry, but it may be moist, and in some diseases profuse sweats may occur, which, sometimes perceptibly, sometimes scarcely at all, reduce the temperature. Such perspirations may cause an eruption of sudamina, or miliaria. color of the skin over the body is generally normal, unless there are eruptions, such as miliaria, or the specific rashes of scarlatina, measles, typhus, and others. But the face is often flushed, especially at the commencement of a fever; often the cheeks and lips are flushed, and the face is elsewhere pale; later on, with a failing circulation, the face becomes deeply congested or livid, and the extremities show the same change.

Alimentary System.-The tongue becomes furred; generally, at first, the fur is white, and the tongue is still moist; then the tongue becomes dry, the fur peels from the edges or tip, and shows the bright red tongue beneath. Later on, the tongue becomes very dry, stiff, hard, dirty brown in color, fissured on the surface, and caked with dried remains of saliva, buccal secretions, food, and sometimes blood. In this stage also the gums are covered with a similar collection, which is called sordes. Loss of appetite, or anorexia, is one of the first signs of fever; sometimes sickness is present, and in all cases digestion is feeble. The bowels are usually constipated. The spleen is often slightly, in certain diseases very much, enlarged, and tender. Circulation. The heart's action is quickened, at first excited, then feebler. The pulse ranges from 80 to 120 or more. It is at first full, bounding, and firm; it soon becomes softer and dicrotic; and with high fever it is hyperdicrotic (see The Pulse). In later stages, as the heart becomes more feeble, it is quick, very small, very compressible, running or flickering. With progressive weakening of the heart's action, the first sound becomes faint, or inaudible, and the impulse may be detected outside the nipple, showing that the heart is becoming dilated..

Respiration. This is quickened in proportion to the pulse and the rise of temperature: it may rise to 30 or 40 in the minute. When the illness has lasted some time, the bases of the lungs become congested (hypostatic congestion), and the respiratory movements of the upper part of the chest in front are exaggerated.

Kidneys.-The urine in fever is scanty, high-colored, and deposits a brick-red sediment of lithates on cooling. The urea is in excess, and the chlorides are usually diminished. In severe febrile illnesses, there may be a small quantity of albumin.

Nervous System.-Headache is common at the commencement of pyrexia ; there is also a heavy feeling, dullness or disinclination to think or make any mental effort after a time, the patient not only does not wish to, but cannot exert the intellect; he becomes drowsy, and when he drops off to sleep, begins to talk. Later on he is delirious without really sleeping, and the delirium may be muttering, and is occasionally maniacal, the patient getting out of bed, struggling with his nurses or attendants, or jumping out of the window. In the last stages there is profound unconsciousness or coma. The disturbance of the muscular system shows itself in general bodily

weakness, tremor of tongue or limbs when they are moved, and twitching of the muscles (subsultus tendinum).

Daily Variations.-The temperature in fever shows daily fluctuations, which are, as a rule, similar to those observed in health—that is to say, the temperature is lower in the morning, higher in the evening; and the lowest point is commonly reached about midnight or 2 A.M., and the highest from 4 to 6 P.M. Occasionally the reverse obtains, the temperature is highest in the morning, lowest in the evening-typus inversus. The pulse and respiration rise and fall with the temperature, and the general discomforts of the patient vary in the same manner.

Varieties of Pyrexia.-The pyrexia which accompanies or constitutes an illness may be one of three kinds: it may be continuous, remittent, or intermittent (Fig. 1). A continuous fever is one in which the temperature is constantly above the normal, and the differences between the morning and evening temperatures never exceed the variation in health-that is, one and