Irregularity of the pulse may be caused by disease of the brain, heart, stomach, or liver; by the disordered condition of the nervous system; by lack of muscular nutrition, as in gout, rheumatism, or convulsions; by deficiency of the heart's effective power, when the pulse-wave does not reach the wrist, or when it intermits and then becomes more rapid in consequence of septic changes of the blood, as in diphtheria, erysipelas, and eruptive fevers. PAIN. The import of pain depends on its seat, intensity, nature, and duration. An acute, intense pain usually indicates inflammation of a nerve as well as the adjacent parts. Sharp, shooting, lancinating pains occur in inflammation of the serous tissues, as in pleurisy. A smarting, stinging pain attends inflammation of the mucous membrane. Acute pain is generally remittent and not fixed to one spot. Dull, heavy pain is more persistent, and is present in congestions, or when the substance of an organ is inflamed, and it often precedes hemorrhage. Burning pain characterizes violent inflammations involving the skin and subjacent cellular tissue, as in case of boils and carbuncles. Deep, perforating pain accompanies inflammation of the bones, or of their enveloping membranes. Gnawing, biting, lancinating pain attends cancers. The location of pain is not always at the seat of the disease. In hip-disease, the pain is not first felt in the hip, but in the knee-joint. In chronic inflammation of the liver, the pain is generally most severe in the right shoulder and arm. Disease of the kidneys occasionally produces numbness of the thigh and drawing up of the testicle, and commonly causes colicky pains. Inflammation of the meninges of the brain is often indicated by nausea and vomiting before attention is directed to the head. These illustrations are sufficient to show that pain often takes place in some part remote from the disease. In chronic, abdominal affections, rheumatic fevers, gout, and syphilis, the entire system is thrown into a morbid state, the nervous system is disturbed, and wandering pains manifest themselves in different parts of the body. Fixed pain, which is increased by pressure, indicates inflammation. If it be due only to irritation, pressure will not increase it. Some rheumatic affections and neuralgia not only bear pressure, but the pain diminishes under it. Permanent pain shows that the structures of an organ are inflamed, while intermittent pain is a sign of neuralgia, gout, or rheumatism. Absence of pain in any disease, where ordinarily it should be present, is an unfavorable sign. Internal pain, after a favorable crisis, is a bad omen. Or, if pains cease suddenly without the other symptoms abating, the import is bad. If, however, pain and fever remit simultaneously and the secretions continue, it is a favorable sign.