It has been stated that the circulation languishes with the diminished energy in the sensorial faculties, and the loss of power in the muscles of locomotion. After awhile, the pulse which was feebler than natural becomes more full, more strong, and generally more quick than in a sound state; and now the skin, which was cold, becomes preternaturally hot. The previous cold consisted, for the most part, of altered sensation, there being little or no loss of caloric: but the feeling of heat, on the contrary, is the result of an actual increase of temperature; for the heat in the interior of the body, as well as on the surface, rises in some cases several degrees, as is ascertained by the thermometer; the range of increase being from the natural standard 98° to 105°, beyond which it is seldom found to augment in this form of fever. The heat is at first not uniform over the entire surface of the body: it often happens that some parts are cold while others are burning hot. The heat is oftentimes particularly intense over the forehead, or over the back part of the head, or over the whole scalp, while the cheeks are commonly flushed. All these symptoms denote a morbid condition in the action of the heart and arteries. Since the generation of animal heat is so intimately connected with the circulating and the respiratory functions, it is probable that the increase of temperature is the result of some morbid action of the capillary vessels belonging to these systems. What the disordered action of these vessels is, which produces increase of temperature, we do not know, because we do not know what their natural action is which produces the temperature of health: but the object of scientific observation is in some degree accomplished, when it is ascertained that one condition of these functions is invariably connected with a morbidly-diminished temperature; another with a morbidly-augmented temperature; and another with the temperature of health. Immediately the circulation is thus excited, the functions of secretion and excretion become deranged. The mouth is now dry and parched; the tongue begins to be covered with fur; thirst comes on; the secretion of the liver, probably also of the pancreas, and certainly of the mucous membrane lining the whole alimentary canal, is vitiated, as is proved by the unnatural quantity, colour, and fetor of the evacuations; the urine likewise is altered in appearance, and the skin is not more remarkable for the sense of heat, than for that of dryness and harshness which it communicates to the touch. With the excitement of the pulse and the increase of the heat, the pain in the back and limbs and the general febrile uneasiness are much augmented.