It is seldom that these symptoms exist long before positive pain is felt. With very few exceptions pain is first felt in the back or loins and then in the limbs. It is rare that this symptom is absent in the commencement of this form of fever, and it often occasions more uneasiness to the patient than any thing else during the first stage of the disease. Already a remarkable change is commonly visible in the countenance. Its expression is that of dejection: it is often strikingly similar to that of a very weak person suffering from fatigue. The colour of the face is pallid, and the features are somewhat shrunk; but its general aspect is so peculiar and characteristic that an experienced eye can distinguish the disease even at this early period, and without asking a single question. The skin partakes in a remarkable degree of the debility which so early shows itself in the muscles of locomotion. This is indicated in a striking manner by its increased sensitiveness to the physical agents by which it is surrounded, and by its inability to resist their influence. Ordinary degrees of temperature produce a sensation of cold which is sometimes intolerable: chilliness is felt even in a heated room, or in a warm bed: hence the sensation of cold, sometimes increasing to shivering, which has been considered one of the most constant signs of fever. But this feeling of chilliness by no means depends on external temperature: it is increased by cold, but it exists in spite of an elevated temperature: it arises from an internal cause, and is not to be counteracted by external heat. While the patient experiences the sensation of cold, there is no diminution of the quantity of caloric in the system. The thermometer applied to any part of the body commonly rises as high as in the state of health, and the skin, touched by the hand of another person, communicates not the feeling of cold, but often, on the contrary, that of preternatural heat. There is no positive abstraction of caloric from the body nor any failure in the process, whatever it be, by which animal heat is generated; there is only altered sensation, in consequence of derangement in the function of the skin. In this form of fever, the chilliness in many cases never amounts to shivering; in others, there is an attack of well-marked rigor, and in others, again, there is either no feeling of cold, or it is so slight that it escapes observation. The symptoms now enumerated are all clearly referrible to derangement of the function of the spinal cord and brain. There is as yet no affection of any other organ obviously or, at least, much developed. The circulating system, it is true, is just beginning to be affected. The pulse is no longer perfectly natural. It is more languid than in the state of health; sometimes it is also quicker: at other times it is slower; now and then it is scarcely changed in frequency, but its action is invariably weaker than in its sound state.