Electro-physiology and electro-therapeutics : showing the best methods for the medical uses of electricity / By Alfred C. Garratt.

by applying rather strong electro-magnetic currents to the two nerves vagi, on either side of the neck, that not only does the heart lessen its action, or totally cease action, but that respira- tion also stopped, and that the eyeballs were greatly protruded from their sockets. From this he inferred that there is at the same time an action of the vagi, both upwards and downwards; i. e., to the central organs, and to the viscera of the thorax. If the vagi be cut across and let alone, the actions of the heart rapidly increase, until they run wild, so that the number or fre- quency of the pulsations cannot be counted. We therefore know that the vagi is the regulator, and not the motor of the heart; and further, when very quick pulsations of the heart are occurring, we know that the vagi is paralyzed, or approaching a state of paralysis; or else the sympathetic nerve is conveying from the nerve centres some increased abnormal stimulus. Faradaizing the nerves vagi, actively, ivhile intact, we get the cessation of the heart's action, and also that of respiration ; and the eyes greatly protrude. But if we cut the vagi across, as can be done in the living dog, and then apply the electric stimulus to the lower cut end of the nerve, it does not stop the respiratory motions, as might be expected, but it does effectually put a stop to the pulsations of the heart and arteries; and, moreover, it usually causes vomiting. But if the upper end of the cut nerve be electrized by the same current of electricity, no effect what- ever is produced upon the movements of the heart, nor yet is the respiration disturbed, provided the current is a moderate one; but if a stronger current be employed, we then see that respira- tion is suspended, and that always during inspiration ; that the blood in the carotid arteries becomes black ; that there is a pas- sive injection of a dark color, of the membranes of the mouth, throat, nose, and eyes, from the asphyxia; and yet the carotid arteries continue to pulsate. If this is not carried too far, and the electrizing is discontinued, the respiration is gradually re- stored, and finally their force and frequency become greater than before the electric stimulus was first applied. M. Bernard also found that, under these circumstances, the blood, the cerebro- spinal fluid, and the bile, all contained sugar; that the secretion 22*