408 MUSCULAR MOTION. 



physical organization, it must, likewise, be endowed with a property 

 essentially vital ; in other words, with irritability or contractility. The 

 cause of the ordinary contraction of muscles is, doubtless s the nervous 

 influx ; but if we materially alter the condition of the muscle, although 

 the nervous influx may be properly transmitted to it, there will be no 

 contraction. This applies to the living animal; but not apparently to 

 the dead; for Valentin 1 found, that after tying the femoral artery or 

 vein, or dividing the sciatic nerve in frogs, the full strength of the 

 muscle remained unaltered for several days, in one case for twelve. 

 We moreover find, that after a muscle has acted for some time, it be- 

 comes fatigued, notwithstanding volition may regularly direct the nerv- 

 ous influx to it ; and that it requires repose, before it is again capable 

 of executing its functions. 



In the upper classes of animals, contractility remains for some time 

 after dissolution; in the lower, especially in the amphibia, the period 

 during which it is evinced on the application of appropriate stimuli is 

 much greater. From experiments on the bodies of executed criminals, 

 M. Nysten found that irritability ceased in the following order of parts. 

 The left ventricle of the heart first; the intestinal canal at the end of 

 forty-five or fifty-five minutes; the urinary bladder at nearly the same 

 time; the right ventricle after the lapse of an hour; the oesophagus at 

 the end of an hour and a half; the iris a quarter of an hour later; the 

 muscles of animal life somewhat later; and lastly, the auricles of the 

 heart, especially the right, which, in one instance, under the influence 

 of galvanism, contracted sixteen and a half hours after death. These 

 results are singular; and the experiments merit repetition. It is, in- 

 deed, strange, that muscles of organic life, apparently circumstanced so 

 much alike, should vary so greatly in the length of time during which 

 they retain their irritability. 



One of the most interesting of the many experiments that have been 

 made on the bodies of criminals recently deceased, for the purpose of 

 exhibiting the effects of galvanism on muscular irritability, is detailed 

 by Dr. Ure. 2 The subject was a murderer, named Clydesdale; a middle- 

 sized athletic man, about thirty years of age. He was suspended from 

 the gallows nearly an hour, and made no convulsive struggle after he 

 dropped. He was taken to the theatre of the Glasgow University about 

 ten minutes after he was cut down. His face had a perfectly natural 

 aspect, being neither livid nor tumefied ; and there was no dislocation 

 of the neck. In the first experiment, a large incision was made into 

 the nape of the neck, close below the occiput, and the spinal marrow 

 was brought into view. A considerable incision was made, at the same 

 time, into the left hip, through the glutaeus maximus muscle, so as to 

 expose the sciatic nerve; 3 and a small cut was made in the heel; from 



1 Lehrbuch der Physiologie des Menschen, ii. 176-92, Braunschweig, 1844. 



2 Art. Galvanism, in Diet, of Chemistry, Hare and Bache ; s Amer. edit., Philad., 1821. 



8 It is not indispensable, in these experiments, to expose the nerve. The author has long 

 known, that, in the case of the frog, it is needless ; and, in his experiments, he has been in the 

 habit of acting under this knowledge. The experiments made on three criminals, two of 

 whom were executed at Philadelphia, and the third at Lancaster, Pennsylvania showed, 

 indeed, that the effect was even greater when the nerves were not exposed. It was found, 

 too, to be more marked when the current was transmitted from the peripheral extremity of 



