While a number of causes of true cardiac pain may be eliminated by improvement in any loss of compensation, by improvement of the heart tone, by more or less recovery from myocardial or endocardial inflammation, and by the withdrawal of nicotin, which may cause cardiac pains, still, true angina pectoris once occurring is likely to be caused by a progressive, incurable condition, and the attacks will become more frequent until the final one. It is possible that a true angina may be due to a coronary artery disease or obstruction, and that a collateral circulation may become established and repair the deficiency. While this probably can take place, it must be rare. Occasionally when the intense pain has ceased, the patient may be nauseated and actually vomit, or he may soon pass a large amount of urine of low specific gravity, or have a copious movement of the bowels. The first attack, and subsequent ones more and more readily, are precipitated by any exertion which increases the work of the heart, as walking up hill, walking against the wind, going upstairs, physical strains, as suddenly getting out of bed, leaning over to put on the shoes, straining at stool, or even mental excitement. Exertion directly after eating a large meal is especially liable to precipitate an attack. Food which does not readily digest, or food which causes gastric flatulence may precipitate attacks. Any indiscretion in the use of coffee, tea, alcohol or tobacco may be the cause of the attack. For treatment of the immediate pain, if the physician arrives soon enough, anything may be given which quickly relieves local or general arterial spasm and spasm of the muscles. The moment that the heart and its arterioles relax, the attack is often over. The most quickly acting drug for this purpose is amyl nitrite, inhaled. If amyl nitrite is not at hand, or has been found previously to cause considerable disturbance of the head or a feeling of prolonged faintness, nitroglycerin is the next most rapidly acting drug. It may be given hypodermically, or a tablet may be dissolved on the tongue. The amyl nitrite should be in the emergency case of the physician in the form of ampules, or may be carried by the patient after he has had one or more attacks. The ampules now come made of very thin glass with an absorbent and silk covering ready for crushing with the fingers, and are thus immediately ready for inhalation. One of these is generally all that it is necessary to use at any one time. Nitroglycerin, if given hypodermically, should be in dose of 1/100 grain. If given by mouth the dose should be the same, repeated in ten minutes if the pain has not stopped. Almost coincidently with the administration of nitroglycerin or the amyl nitrite, a hypodermic injection of 1/8 or 1/6 grain of morphin sulphate should be given without atropin, as full relaxation is desired without any stimulation of atropin.