clearest-headed practitioners have been those who studied disease as a naturalist studies a group of plants or animals; and then a species, with its variations. So in medicine there are groups of diseases like malnutrition in its various forms, and] pyrexia, for instance; and the first step is to get up the outlines of each group; next, the features of each malady; after which the individual peculiarities are easily recognised. The study of the natural history of a disease includes its temperature curve, if it has one. Familiarity with the outline of the disease will enable the detection of any singularity to be readily made; and what is more, makes its explanation readily apparent, at least in most cases.

Then, again, there are associations of temperature-variations to be taken into account, and ranged alongside the evidence of the thermometer. Thus, as Senator points out, there can be no evaporation of water demonstrated in rising fever. While in defervescence there is well-marked perspiration and exhalation of water, by which the heat-loss is made very considerable. Consequently, if the temperature show a fall (and this is not due to an imperfect observation, for that is always the point to be sure about when the temperature is below what might be anticipated) in a pyrexial case, and there be no perspiration, the question arises at once, Is this 'defervescence?' or is there something else in action? In other words, the instrument must be wielded intelligently, like the stethoscope. Some men hear something distinctly, but what its pathological correlative is they cannot tell; the same men look at the index of their thermometer in a vague way, and either can form no conclusion therefrom, or jump to some conclusion by no means necessarily a correct one. Some men are always making observations but they never make deductions at all commensurate with their observations, either as to the case in connection with which they are made; or anything else. It is easy to make an observation with an instrument of precision, but

individual thought, the sweat of the brow, is indispensable to correct interpretation of it when made.

Whenever there is a high temperature steadily maintained, there will be found either a febrile condition with its own features and complications; or a local cause with its special characteristics at least, as a general rule. In women there are, however, hysterical temperatures;' or there are pyrexial storms corresponding to the catamenial periods, if carefully hunted out. In one case a sharp pyrexia came on in a lady a month after her confinement, and ran on to the production of the typhoid condition; without any apparent cause. When pressed to give it a name, the old expression, nervous fever,' was all that could be said. The patient recovered under anti-pyretic measures, but at the end of three weeks the temperature rose again. On careful examination, it was found these 'pyrexial storms' corresponded to the times of the catamenial weeks; had impregnation not occurred. The careful practitioner, when puzzled with a pyrexia in a woman during the child-bearing period, should never forget the catamenial week of the mensual cycle; this may not only prevent his making a blunder, but may secure him no little credit.

Thermometrical observations are not free from sources of fallacy, and may mislead unless these observations are corrected by other observations. The finer the instrument of precision, the more knowledge is requisite to wield it wisely; and the wider the diagnostic grasp, the more valuable will each precise observation become. Clinical observations are to be read as Opie mixed his colours-' with brains, sir!' For instance, there exists a consolidation of a lung-apex, with a moist râle in the middle of it; this may be a local bronchial râle, or it may indicate softening. The evening temperature will commonly decide the question: and a very important matter this often is. Again, the thermometer will tell of rising pyrexia, even despite energetic, wise

treatment; and its voice is then that of a prophet, albeit a prophet of evil. At other times, it is the herald of good news-of commencing defervescence. The clinical thermometer and the watch are instruments of precision of price

less value; yet, be it remembered, it is physiological disturbance which gives them their value!

Having thoroughly comprehended what has been written about temperature-curves-viz., that a typical curve can

For

only possess a general outline-it may be well to consider the temperature-curve of some common maladies. instance, compare the curve of ordinary scarlatina with that of measles. The highest point is reached early in the

pyrexia in scarlatina, while in measles it comes just before the defervescence.

Then the curve of varioloid contrasts with the tracing of small-pox, terminating fatally with a sharp pyrexial

rise.

Then, again, the long curve of a typical ordinary case of enteric fever presents a character quite unlike the tracings

Fah C1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 105-8 41

Enteric Fever.

of the temperature in relapsing, or famine fever. The one is a long, flat curve, while the other has a broken, crag-like outline.

Fah C 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21

Relapsing Fever.

Relapsing fever is a sharp, sudden pyrexia. Still, when a relapse occurs in case of typhoid fever, the curve of the relapse is so much like that of relapsing fever, that it is unnecessary to give it here.

Of like character as brief but sharp pyrexia is the tracing of erysipelas, contrasting with the curve of severe typhus fever.

The curves of typhus and of enteric, or typhoid fever tell of an illness which involves a considerable time; though in some cases the fever is cut short, or in other words 'aborts;' and then the tracing approaches the short curve given at p. 167.