734 DR FRASER ON THE PHYSIOLOGICAL ACTION 



Action on the Spinal Cord. 



Having now excluded the encephalon, muscles and spinal nerves, we are 

 led to conclude that the production of the paralysis by physostigma is due to an 

 action on the spinal cord. Such an opinion was originally expressed by myself 

 after a careful general consideration of the symptoms, but no subsequent inves- 

 tigator has coincided with my theory except Laschkewich,* from whose excellent 

 paper I have derived more than one hint for the further and special examination 

 of the spinal effects of Calabar bean. 



I quote the following experiment from my previous paper on this subject, as 

 it affords an excellent example of those general paralytic symptoms that first 

 induced me to refer the principal neurotic action of physostigma to the spinal 

 cord. 



Experiment XXXV. 



" Five and a-half grains of the fine powder of the kernel were made into pills, and swallowed 

 by a buck rabbit, eight months old. 



" A slight degree of paralysis was seen in the posterior regions, in ten minutes, and, soon 

 after, they yielded, the anterior portion of the trunk remaining supported by the fore-limbs. 

 In fifteen minutes, the fore-legs gave way, and faeces were passed. In twenty minutes, the 

 respirations became noisy, reflex action was not abolished, and the pupils contracted. In thirty 

 minutes, the rabbit submitted to be placed in any position. In thirty-five minutes, the respira- 

 tions became extremely noisy, and accompanied with muscidar spasm. Faeces and urine were 

 passed, and reflex action could not be induced by puncturing the skin. General, but slight, 

 muscular spasms now occurred frequently ; the eyelids did not contract when the eyeball was 

 pricked, and the respiratory stertor ceased. In forty minutes, a general spasmodic contraction 

 of the muscles occurred, and, in forty-one minutes, all respiratory movement had ceased. 



" Autopsy, immediate. The cut muscles contracted. The heart was acting at the rate of 

 seventy-two per minute ; and this ratio gradually diminished till it ceased, thirteen minutes 

 after death. The brain was rather darker than usual, and no change could be perceived in the 

 spinal cord. The cerebro-spinal fluid was in abnormal abundance. The large veins were 

 distended, and the right chambers of the heart were engorged with dark blood. . . . The ver- 

 micular action of the intestines was well marked, and all the viscera contained an abnormal 

 excess of dark blood. The muscular system was flaccid, but contractions could be caused by 

 irritation of the nerves." 



This experiment formed one of a series undertaken to discover the smallest 

 dose which could produce death in a full grown rabbit. f The quantity employed, 

 five and a-half grains of the kernel, was the smallest that could do so. 



As evidence of the same character, I add the following from many subsequent 



experiments : — 



Experiment XXXVI. 



One grain and a-half of extract, suspended in fifteen minims of distilled water, was injected 

 into the abdomen of a small collie dog. The animal was rapidly affected with inability to 



* Virchow's Arcliiv. Februar, 1866. j Op. cit. sect. v. experiment viii. 



