• ON MUSCULAR IRRITABILITY. 159 



I will now cite two or three experiments in illustration of this exalted 

 state. 



April 7, 1863.— A frog carefully etherized, was placed upon his back, and 

 the heart was excised. The frog was then left till the following morning, a 

 *period of 13 hours. At this time the webs and toes were in a diied stale ; 

 but the muscles responded with extreme readiness to slight blows, but were 

 n^ thrown into contraction when pinched by forceps. They were very 

 susceptible to weak galvanism. These observations on the muscular system 

 having been made, the nervous system was tested by removing the head and 

 attempting to irritate the cord. Galvanizing the cord would not excite the 

 muscles even when a copper wire was thrust low down into its substance. 

 The cord, in fact, seemed quite incapable of either initiating or conveyin^^ 

 any stimulus to the muscles. The sciatic nerve was now raised upon a glass 

 tube, and it was found that it could not be excited by the strongest galvanism 

 The neurility or special life of the nervous system was in fact gone; ivMle 

 the peculiar life of muscular structure, viz. its irritability, had become preter- 

 naturally exalted. 



Another frog having been etherized till incapable of exhibiting any reflex 

 phenomena (that is to say, until the nervous system was temporarily extin- 

 gmshed), the muscular system was stm, under these conditions, highly sensi- 

 tive to galvamsm. The frog did not recover from the etherization. It was 

 aUowed to remam aU night ; and its muscles were stiU foimd susceptible to 

 galvanism in a high degree, but not to other modes of stimulation. The 

 nervous matter of the cord was now broken down and removed, and the body 

 placed m a little water to prevent desiccation. It was again left aH nio-ht • 

 and on the foUowmg morning the muscles were found to be exceedinqh, sus- 

 ceptible to slight bloivs or pinching s including not only the skin but also a small 

 portion of muscular substance. These motions simulated in their extent and 

 power volitionid movements. They were excited with the utmost ease, and 

 seemed to ordinary observers to be purposive acts resulting from sensation. 

 Ihese effects were observed 36 hours after the etherization of the creature 



May 18, 1863.— A frog having died in spacing, the muscles were found 

 to be somewhat susceptible to sHght blows, and very susceptible to galvanism 

 A portion of the calvarium was removed so as to aUow the brain and cord to 

 be tested. A copper wu-e was thrust into the canal, and an attempt made to 

 galvanize the cord, but with no result ; ndthor did any contraction take place 

 durmg the fina destruction of the cord. In fact, the nerve-tissue was dead 

 and could not be stimulated. This frog being left in this condition for 15 

 hours, the muscles of the thigh of one limb were found to be peculiarly 

 susceptible to the influence of both sHght blows and galvanism ; and when a 

 contraction was excited, the limb wasforcibhf raised or draivn up, and re- 

 mained so for several seconds. After a few minutes' experimentation, in which 

 many contractions were produced, the force appeared to be exhausted ■ hence 

 It seemed that the force Tvhich confers contractiHty AacZ accumulated to a 

 certain pitch or intensity, and ivas used up in the act of contraction. The fol- 

 i^flaa "" Tn ""tT^ observation, from my experiment-book. 9 a.m. August 

 Id, 1866. 'On taking up this frog, noiv dead, and touching the limb, with 

 my finger, which during ife had been paralyzed by section of its nerve, ^'^ was 

 suddenly shot out as if alive. I placed the body down, and one or two appa. 

 rently spontaneous movements of smaU extent afterwards occurred. On touch- 

 ing the skin gently with the point of a needle, by the slight pressure upon 

 the muscle beneath, movements of the Hmb were also induced ■, but this Lh 

 degree of exaltation very rapidly disappeared, after which the muscles were 



