In discussing the diseases of the intestinal canal, we shall have to refer not merely to the great fact of the frequency of the stools, but their appearance and consistence will be found each to have a definite bearing on diagnosis. The existence of constipation or diarrhoea deprives a coated tongue of much of its importance, considered with reference to a general state of system. Hence the value of the observation is in proportion to the explanation it affords of the appearance of the tongue. It is also sometimes suggestive of disease in remote organs, of which the diarrhcna of phthisis, and the constipa tion attendant on inflammation of the brain may be taken as examples.
With regard to the urine it may be remarked, that while an abundance of pale limpid urine entirely negatives the idea of acute or febrile disease, an opposite state, its being scanty and loaded, although a constant concomitant of such disorders, may depend on a great variety of causes; and is of import ance chiefly when conjoined with thirst. The special diagnosis must'be defer red to a later stage of the in ; but in the present day, with all the advantages of chemical analysis, something more ought in all cases to be done, than merely to ascertain the amount of the secretion or the degree of its turbidity.
e. In regard to thirst it may be stated, as a general rule, that the dryness of the tongue and the desire for liquids are proportionate to each other. All febrile states present this phenomenon in greater or less degree, and too much importance must not be attached to its presence, inasmuch as copious dis charges from the bowels or kidneys invariably give rise to it, whether there be ever or not. The only chronic states in which it is very marked, are diabetes, and its simulation, diuresis. In the former, it is accompanied by hunger even in a more remarkable degree.
Loss of appetite is so common that it hardly needs to be inquired into, ex cept for the purpose of noting as an important symptom the circumstance of the appetite being unimpaired in cases where other indications would lead us to expect it should have been lost.
§ 2. The general appearance of the patient affords to the phy sician very distinct indications of the nature of the disease, and of the organ in which it is probably located. This group ought to be studied with care, because they are apt to lead to hasty conclusions.
a. Alterations in general bulk are chiefly important as evidence of long-continued diseased action. Emaciation implies imperfect nutrition depending on a variety of causes, which are generally slow in their operation. It also sometimes supervenes very rapidly in acute febrile disorders; but here the cause is unequivocal. In chronic maladies it arises either from deficiency, from waste, or from perversion of the blood-plasma or nutritive material. Hence it occurs in organic diseases of the abdominal organs, in suppura tions and diabetes, in phthisis and cancer, in its greatest degrees.
Along with some general resemblance in all these cases, there are certain special characteristics forming part of what may be called the physiognomy of disease, which materially aid an experienced eye in forming a diagnosis quickly ; but too much reliance is not to be placed on them, and their only use is in directing the practitioner where he is to look for disease, the nature of which must be afterwards determined by its own special phenomena.
General increase of bulk, as obesity, is to be regarded as a diseased state, but it cannot be traced to any special organ as its source. It may also arise from universal anasarca, and in rare cases from universal emphysema. The doughy feeling of the one, accompanied by the remaining mark of the finger known as pitting on pressure, contrasts strikingly with the elasticity of the other, and the peculiar sensation of crepitation it conveys to the hand of the observer.
It is worthy of remark that in what has been called acute dropsy, especially as occurring in children after scarlatina, the increase in size sometimes has a feeling of elasticity, and scarcely seems to pit at all. Firm continued pres sure over a superficial bone, such as the tibia, will remove any doubt. In such a case, I have heard the suggestion thrown out whether the case might not be one of emphysema.
Local changes of size are more particularly connected with local disease ; those which are attended by increase will be discussed separately under the head of morbid growths ' • those characterized by emaciation have their source in imperfect nutrition of the part, and are merely the concomitants of some other more important lesion ; e. g., the wasting of a limb which is the subject of paralysis.