Morgagni first of all seems to have realized what was the mechanism by which alcohol injures the human system. He pointed out that the excitation of the heart due to the action of alcohol was reflected in an overdistention of the arteries. This overdistention gradually led to degenerations in the arterial walls. The loss of elasticity thus induced brought on a disturbance of the circulation in the important organs of the body, and so gave rise to symptoms of wide-spread interference with organic functions. Morgagni's studies in aneurism, that is, in the dilatation of bloodvessels, show how thoroughly he understood the mechanism of the formation of this serious pathological {44} condition. He pointed out that the first noticeable disease change that occurs is a degeneration of the inner coat of the artery. This leads to the formation of furrows on the inner wall of the vessels and finally brings on weakness of the middle coat of the artery. He realized that the progress of these arterial changes is due to a large extent to blood pressure within the arteries. He felt, too, that blood pressure could be kept from being dangerously high by strict attention to diet limitation. If aneurisms are discovered in early stages the patient's life may well be prolonged by these simple measures. This idea contains the germ of the Tufnell treatment, which has been the most successful therapeutic measure for the treatment of aneurism in the nineteenth century. The Italian anatomist's acumen led him to appreciate better than ever before in medical history the influence of the mind on the circulation. He pointed out that emotions have a powerful influence on the circulatory system in all its parts. How much the peripheral bloodvessels are affected can be seen in the tendency to blushing during certain forms of excitement, involving shame or embarrassment; on the contrary, pallor in anger, or indignation, or fright. He pointed out, too, that the heart is affected by such emotions and is sometimes strenuously excited and sometimes very much retarded. Morgagni understood that the influence of such emotions in especially excitable individuals leads to wear and tear on the bloodvessels and so to a shortening of lives. He thought of some aneurisms, even those affecting the large bloodvessels, might be caused by sudden intense emotions, and especially by violent efforts to suppress or conceal emotions. We know now, however, that these pathological conditions are due to human passions, but quite other than those which Morgagni had in mind.