The influence of the condition of the capillary circulation upon that of the arterial system and the heart is manifest in inflammations. By reflex excitation the arteries are made to contract actively and impel the blood more forcibly than in the normal state toward the centre of impeded nutrition (stasis). This has been abundantly proved by the comparison of the amount of blood flowing through the arteries of a sound limb and those of its fellow, when the latter is the seat of a violent acute inflammation. Blood-states also affect the pulse by the differences in direct stimulation to which the heart and arteries are subjected according to the qualities and composition of the blood. It is probable that the fever-pulse of typhus, typhoid, the exanthemata, septicæmia, and pyæmia has its origin in morbid conditions of the blood, acting in a twofold manner--directly upon the heart and arteries themselves, and mediately through the vaso-motor ganglia. Lastly, the nervous system stands in an important relation to the action of the heart and arteries, and thus to the pulse. In a nervous, excitable person, changes in the rate of the pulse may take place, with slight significance, which in a different constitution might be of serious import. To understand the language of the pulse care must be taken in several respects: 1. Both wrists should be felt. Sometimes there is an abnormal variation in the course of the main radial trunk which may pass over the thumb. Again, an aneurism may cause a great difference between the two radial pulses, or, possibly, an embolus may occlude one of the radial vessels, annulling its pulsation. 2. Other arteries also, especially the carotids, should be examined--in all obscure cases at least. Visibly beating, distended, and tortuous temporal arteries are occasionally met with. They are not pathognomonic of any one malady, although often referred to the gouty diathesis. They {154} may attend irregular malarial attacks, or may be connected simply with a hyperæmic state of the brain. 3. The heart's impulse should always be compared with the arterial pulsation. The former may be strong and regular, while the latter is small, feeble, or intermittent. Something must then be wrong, either in the aortic valves or in the arterial system. 5. On account of possible nervous agitation, the pulse should usually be examined more than once, during each visit to the patient.