Electro-physiology and electro-therapeutics : showing the best methods for the medical uses of electricity / By Alfred C. Garratt.
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due to the attraction of greater quantities of arterial blood, that is always induced by the action of the current; and that the excretion of the saliva is effected by the same forces which at- tract the blood to the glands, and not by the tissue of the glands themselves, since the elementary substance of the salivary glands has no inherent contractile power. But if the above nerves are excited, according to Professor Bernard, the amount of saliva which may be gathered in a very little time from the salivary glands will be found to far exceed the volume of the entire glands themselves, so that it cannot be shown that the saliva is simply squeezed out of the gland. It is thus proved that the secretion occurs in the salivary glands at the very moment when the electric current is made to traverse these nerves of secretion. If the sympathetic nerve is traversed by the current, neither the normal nor abnormal secretion is then induced, but, on the con- trary, all salivary secretion is arrested. When the abdomen of a recently-killed animal is quickly opened and exposed to the air, particularly if a cool air is blow- ing over it, the small intestines are seen to contract, dilate, and move, from the contact with the air. But very soon these con- tractions cease. If, now, the poles of an electro-magnetic cur- rent be brought in contact with any portion of the intestines, — say on the ilium, — they will renew the contractions, and urge the contents of the canal towards their receptacle, the rectum. But observe: if the electrodes are applied near each other, — say on some portion of the duodenum, and retained there for a minute, and are then very quickly withdrawn from it, — the contraction that has been thus induced at that place continues, and increasing- for a little time after the electrodes are removed, then moderately disappearing. The stomach is more quickly and strongly responsive to the electric stimulus than the duode- num. This latter is rather more so than the small intestines, and they are more so than the colon and rectum. But the sphincter-ani is more prompt and powerful in its response than any portion of the alimentary canal, while the ccecum appears to be the least so. The ductus choledochus and the liver contract notably under the influence of the electric current. If the elec-