At the same time the respiration is affected in a corresponding degree: it is shorter and quicker than natural; the chest does not expand so freely, and compensation seems to be sought in an additional number of respirations. Oftentimes neither the pulse nor the respiration appears to be much altered, if the patient remain perfectly still; but if he rise and walk across the room, the pulse instantly becomes rapid, and the respiration is quickened almost to panting. The transition from the affection of the nervous and sensorial to that of the circulating and the respiratory systems is thus clear and striking. Physiology teaches us how closely these systems are connected, and how mutually they are dependent one upon the other, the closest observers and the ablest experimentalists candidly confessing that they are scarcely able to determine which is the least dependent, or the action of which is the least necessary to the others performance of its functions. The nervous system being first deranged, it is thus consonant to what we know of the healthy function of the animal economy, that the circulating and the respiratory systems should be the next to suffer. How long the nervous system may continue thus deranged, before any other organs are involved, excepting the circulating and the respiratory, to the extent just stated, is uncertain. There can be no doubt that in this mild form of fever, the range of the duration of this isolated state of disorder, if we may so express it, is from a few hours to several days. The rapidity or the slowness with which other systems of organs become involved seems to depend very much upon the acuteness of the attack. In general, the more acute the fever, the more rapidly the individual phenomena succeed each other, and the entire series becomes complete. But this is not, and it is important to bear in mind that it is not invariably the case: for experience teaches us that the severity and danger of the disease are not diminished by the slowness of its approach; and that cases occur, which are slow in forming, and which do not for awhile excite alarm, that ultimately become truly formidable.