show that, both through the vagus and the sympathetic, the most powerful reflex action may be produced in the heart and stomach by irritation of the fifth cranial. Another occasional excitant of angina is an interesting link in the chain of proof that angina is _au fond_ a neuralgia, namely, the malarial poison, which has in a good many well-observed cases distinctly induced the disease.[13] Finally, the occasional influence of excessive tobacco-smoking in producing anginal attacks, in persons not affected with any discoverable organic heart-disease, affords the strongest corroborative evidence of the essentially neurotic character of angina pectoris. M. Beau[14] has recorded many serious, and some fatal, cases from this cause. Probably in both the malarial cases and those induced by tobacco-poisoning the special neurotic tendency existed already. _Diagnosis._--The diagnosis of angina pectoris, in those severe forms with which the popular idea of the disease is chiefly connected, can hardly be a matter of much difficulty. When we see an elderly man lying in a state of deathly collapse, which has suddenly come on, with cold sweats and nearly extinguished pulse, gasping for breath, and complaining of intolerable pain in the chest and arm, and a sense of oppression more dreadful, even, than the pain, we can hardly doubt that the case is angina in its worst form. On the other hand, when a young person, especially a young female, complains even of very severe pain in the cardiac region, together with breathlessness, especially if the heart be palpitating and the face flushed, the diagnosis, though not immediately certain, already very strongly indicates the probability that the case is not one of primary cardiac neuralgia at all. These are extreme instances, however. In more doubtful cases, the following are the principal materials for decision: _Affirmative Signs._ _Negative Signs._ 1. Age over forty. 1. Age under forty. 2. Male sex. 2. Female sex. 3. Nervous temperament (personal 3. Temperament either not nervous and family) without marked at all, or markedly hysterical hysteria or hypochondriasis. or hypochondriacal. 4. Existence of arterial 4. No signs of arterial degeneration. degeneration. 5. Existence of valvular disease 5. No discernible valvular of the heart. disease. 6. Extension of the pain to 6. Heart sounds clear and strong. one or both arms. 7. Vivid sense of approaching 7. Pain fixed to one spot and dissolution. increased or relieved by muscular movements of the painful parts.