Carpenter's principles of human physiology . contraction. It may be observed in the manner first describedby Dr. Stokes§ by percussing the pectoralis muscle of emaciated patients, orby drawing the back -of a knife across a muscle after all signs of irritabilityon the application of stimuli to the motor nerve have ceased; it then presentsitself as a swelling or intumescence a few lines broad and high, but varyingwith the strength of the blow, lasting for four or five seconds, and slowly dis-appearing. Kronecker and Stirling|| found that the red muscles of the rabbit, * As in Heidenhaina mechani
Carpenter's principles of human physiology . contraction. It may be observed in the manner first describedby Dr. Stokes§ by percussing the pectoralis muscle of emaciated patients, orby drawing the back -of a knife across a muscle after all signs of irritabilityon the application of stimuli to the motor nerve have ceased; it then presentsitself as a swelling or intumescence a few lines broad and high, but varyingwith the strength of the blow, lasting for four or five seconds, and slowly dis-appearing. Kronecker and Stirling|| found that the red muscles of the rabbit, * As in Heidenhaina mechanical Tetano-motor, in which a little hammer is set in motion by an electro-magnetic current, and a tetanic condition can be established in the muscles which will last for two minutes or more, till the irritability of the nerve is destroyed. t Marey, Rev. desCours Scient., vol. iv. 1867, p. 215. X Brown-Sequards Archives de Physiol., 1874, t. vi. p. 5. § On Diseases of the Chest, p. 397. H Fosters Journal of Physiology, vol. i. p. 395. 3 F. 802 ON THE STRUCTURE AND FUNCTIONS OF MUSCULAR TISSUE. when stimulated with four shocks per second, passed into incomplete tetanus;,*md with ten shocks per second into complete tetanus. The pale muscle ofthe rabbit requires 20-30 shocks per second to be completely tetanized,whilst six induction shocks per second prevent it from becoming completelyextended during the period of stimulation. A further phenomenon has beennoticed in the same muscles by Auerbach* after an energetic blow ; namely,a wave or undulating contraction, proceeding from either side of the localintumescence of SchifF, and propagating itself to the extremity of the muscleat the rate of about eighteen inches per second. The breadth of the wavesis about a quarter of an inch at their base, and they gradually die out as theyspread from the point struck. It is doubtful whether both of these appear-ances are not due simply to a prolonged contraction of the muscle, resultingfrom ex
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