Another very important class of predisposing causes of angina is the mental emotions. It is notorious that the disease is one not common in humble life; it chiefly assails the more cultivated class, and especially men who are much engaged in affairs in which great mental anxiety or emotion is mingled with severe toil of intellect. Thus the professional class has always shown a sad predominance in tendency to this disease; a large number of the victims have been found among overworked clergymen, lawyers, doctors, engineers, etc. The various forms of heart-lesion which have been already mentioned must doubtless be considered highly predisposing, when there is already a neurotic susceptibility, more especially those which, like fatty degeneration of the muscular structure, greatly enfeeble the heart's action. I do not believe that these diseases will cause angina in a person who is free from the peculiar nervous susceptibility. The immediately exciting causes are very various. The most common of all is doubtless some exertion of body, or distress of mind, which at once agitates and embarrasses the heart's action; and, where the tendency to cardiac neuralgia has once declared itself by an actual attack, very slight excesses of this kind will usually suffice to re-excite the paroxysm. Sexual excitement is particularly provocative of the attacks, in the predisposed. But much slighter causes suffice, in those cases where the irritability of the cardiac nerves has become very intense: thus a mere puff of cold air upon the face, and other similar slight peripheral impressions, by acting in a reflex manner, have frequently produced the paroxysm. I have seen an extremely severe anginal attack brought on by the slight shock of the sudden slamming of a door. And it would even appear that some peripheral excitements of a powerful kind may operate with such force as to generate angina in persons who are merely in weak health, but who cannot be supposed to be specially predisposed to angina; it is in this way, I presume, that we must explain the extraordinary occurrence, reported by Guelineau,[10] of an epidemic outbreak of angina, in which numbers of men, belonging to a ship's crew, were simultaneously affected. The men had been badly fed, and their quarters were very unhealthy; but the powerful exciting cause seemed to be the rapid change from a very hot to a very cold climate. Not only were there many cases of severe angina, but other forms of neuralgia, and severe colics, were observed in others of the crew. Among the sources of peripheral irritation which ought to be particularly considered, in relation to angina, are the diseases and injuries which produce powerful irritation of the branches of the trigeminus. Lederer's cases[11] of violent vomiting and cardiac pain, from the operation of pivoting teeth, and Remak's instances[12] of violent palpitation and cardiac distress, produced by disease of the last molar tooth, seem to