in close contact with the fibres of the cranial and cerebrospinal nerves, which they accompany for a short distance, and then branch off to supply the walls of the blood vessels, over which it is their special functions to preside. Other fibres again pass into the gray matter of the hemispheres, and are intimately connected with the nerve cells occupying the cerebral convolutions. Hence, it results that the sympathetic nerves may be influenced not only by external agents acting upon their peripheral extremities, but also by emotional causes influencing their centripetal prolongations. In fact the experiences of daily life continually offer examples of this mode of irritation, the emotions of fear, anger and shame all give rise to external phenomena with which we are familiar, as pallor of the countenance, blushing, &c., &c.

In insanity, when the cerebral activity is far greater than in health, and where a constant flow of the most dissimilar ideas passes through the mind in rapid succession, each in turn calling forth some emotional excitement, the sympathetic centres are subject to continual excitation, and by reflex action manifestly influence the phenomena of the circulation. This centripetal irritation, when continued for a certain time, wears out the excitability of the ganglia, and results in a paralysis of the nerve filaments supplying the circulatory apparatus, in consequence of which, we find a passive dilatation of the smaller arteries and capillaries, with a loss of the normal elasticity of their walls. The free flow of blood from the arterial to the venous system is interfered with, and the result is a sluggish, monocrotic form of pulse. It is not unlikely that cardiographic tracings of the action of the heart itself would show a deviation from the normal rythm, so that the insane pulse may depend not only upon the abnormal condition of the vessels, but also in some degree upon functional disturbance of the cardiac contractions.

In conclusion, I will give a few traces borrowed from Wolff, which corroborate the opinion expressed above with regard to the action of emotional excitement upon the form and rythm of the pulse.

Figure 27, represents the pulse of a patient having

chronic mania during a condition of bodily and mental repose, while figure 28 shows the modification of the

pulse curve caused by the patient's having a strong desire to ask a question.

Figure 29, is the pulse of a patient who exhibited

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slight symptoms of mania, and who presented the pulse trace shown in figure 30, under the influence of excite

ment caused by a desire to complain of bad treatment. As he became still more angry his pulse assumed the form represented in figure 31, and finally being no longer

able to restrain himself, he broke out in a storm of words, and gave the trace figured in figure 32.

In the last case we find that emotional excitement not only influences the form of the pulse, changing it from the dicrotic to the tricrotic type, but it also modifies the cardiac rythm, and produces a kind of intermittence, which continues during the effort to restrain the feelings, and resumes its regular rate as soon as the patient finds relief in an outburst of passion.

From the above, I am of the opinion that in the earliest stage of insanity, when the mental agitation is most acute, we should expect to find a pulse nearly approaching the normal tricrotic type, and in proportion as the excitement diminishes and the patient falls into a state of mental apathy and dementia, the pulse becomes dicrotic, and at last monocrotic, sluggish and flattopped, as a result of the loss of irritability or paralysis of the great sympathetic system.