8. Pain running round one side, but not extending to shoulder or arm. It is scarcely necessary to say that no single one of the above signs is individually of positive worth for the decision, which must be made after a careful review of the comparative arguments, _pro_ and _con_. The disorders with which angina is most likely to be confused are (1) Myalgia of the intercostal or pectoral muscles; (2) intercostal neuralgia; (3) acute commencing pleurisy. Either of these may very perfectly simulate the more formidable disease, as regards the two elements of acute pain and catching of the breath; but the condition of the circulation, taken together with the consideration of the above named points, will generally decide the question. Especially important is the deep persuasion of impending dissolution, when present, as a positively affirmative symptom. It should be born in mind that, if we are summoned to a patient's assistance, and have no previous history to guide us, our diagnosis, to be useful, must be rapid; and it is always better to err on the side of angina than in other directions, and to employ remedies boldly in that sense, if there be any reasonable ground for believing the case to be of that nature. A more mature and careful diagnosis may be made when the patient has recovered from the severe symptoms of the paroxysm. _Prognosis._--The prognosis of cardiac neuralgia is at best doubtful, and, in many cases, positively bad in the highest degree. If the attacks occur for the first time in a patient who has passed middle life, and is physiologically old for his age, _i. e._, shows tendency to degenerative changes of vessels, arcus senilis, gray hair etc., they are of very gloomy import; more especially if any signs exist which make a fatty change in the ventricle probable, or if there be serious valvular lesions. The probability here is greatly in favor of a speedy fatal termination; if the first attack does not kill, a second or third very probably will; at any rate, the patient is not likely to survive any considerable number. If the attack occurs in a younger person, in whom there is not much likelihood that arterial degeneration has seriously commenced, or the heart-muscles become fatty, more especially if the attacks have been brought on by such an accidental circumstance as a very exhausting bout of mental or physical toil, then there is considerable reason to hope that the disease may soon wear itself out. Even patients who have serious valvular lesions may, with young and undegenerated tissues in their favor, quiet down again into a regular habit of semi-health, in which they may live for a long time without any recurrence of cardiac neuralgia. The more purely neurotic form, again, especially when it develops gradually out of some pre-existing