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This historic book may have numerous typos and missing text. Purchasers can download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1824 Excerpt:... two-fold mode of contraction is never met with in the involuntary muscles of the abdomen. Instead of abrupt, sudden contractions, nothing but a slow shrinking, frequently hardly apparent, ia observed; there is not even, properly speaking, total contraction, like that of the heart wherein every fibre of an oracle, or a ventricle, moves at the same time; here each fleshy fibre seems to act in succession. If placed at the origin of the large vessels, the stomach or bladder could not possibly propel the blood in jerks, as it is propelled from an artery at each contraction. On the other hand, the instant motion subsides in the stomach, the intestines, and the bladder, these oscillations, always observed in the heart and in the voluntary muscles, and which may even be produced at will, are never seen. Section v. Motions produced by the Organic Muscles. There is scarcely ever any simple motion in these muscles; the varied interlacement of their fleshy layers causes them generally to act on the substances they contain in three or four different directions. We cannot speak generally of those motions which compose the djastole of the heart, the peristaltic motion of the alimentary tube, the contraction of the bladder, &c. Each muscle has its mechanism that belongs to the physiological history of the function to which it contributes. SECTION V. Phenomena of the Relaxation of the Organic Mttscles. During the relaxation of organic muscles, the phenomena are generally the reverse of the preceding. It is therefore useless to state them: but here is a question to be examined, namely to know what is the nature of that state which succeeds contraction and alternates with it. In the muscles of animal life, when contraction ceases, it is not in general the muscle itself t...