OF THE CALABAR BEAN. 721 



limited to the points of stimulation, until about the time up to which feeble indications of 

 retained contractility could be obtained in the voluntary muscles. 



Experiment VI. — (Temperature of Laboratory between 52° and 54° F.) 



To a frog, weighing 379 grains, four grains of extract were administered in the same way 

 as in the preceding experiment. Motor nerve-conductivity ceased in two hours and sixteen 

 minutes, by which time the exposed muscles were found to have become blue. The cardiac 

 action continued rhythmical, though much reduced in frequency, until twenty-seven hours and 

 fifteen minutes, after which, the auricles alone contracted spontaneously till forty-four hours, and 

 then, spontaneous cardiac action entirely ceased. During all this time, the muscles were flaccid, 

 contracted vigorously on the application of weak galvanism, and had an alkaline reaction 

 and a blue colour. Soon afterwards, they became paler and slightly stiff, but it was not until 

 seventy hours after the administration of the poison that galvanic stimulation failed to produce 

 any contraction ; and then rigor mortis, with an acid reaction of the muscles, set in. 



These three experiments distinctly prove the absence of any paralysing effect 

 by physostigma acting through the blood on striped muscle. 



Rigor mortis is delayed for an unusual period after apparent death in cold- 

 blooded animals, and its appearance, in mammals and birds, is certainly not 

 hastened. In both classes this change in the condition of muscles is only 

 indirectly affected by this substance, and that through its influence on the 

 cardiac contractions. When the blood supply of the muscles is stopped their 

 function is suspended, and rigidity follows ; but the resulting rigor does not seem 

 to be due, in any other than this indirect method, to the action of physostigma. 



This may be more clearly demonstrated b} r detailing one of many experiments 

 in which a portion of the frog was protected from the influence of the poison. 



Experiment VII. — (Temperature of Laboratory between 52° and 54° F.) 



The right iliac artery was exposed, by removing a portion of the sacrum, and tied in a frog, 

 weighing 878 grains. Two minutes afterwards, three grains of extract, suspended in ten minims 

 of distilled water, were injected into the subcutaneous cellular tissue at the right shoulder. In 

 a few minutes, a condition of general paralysis existed, and shortly afterwards the skin of the 

 tied limb was much paler than that elsewhere, this contrast becoming more marked as the experi- 

 ment advanced. In an hour and twenty minutes, the sciatic nerves being exposed, it was 

 found that the left was completely paralysed ; while galvanism, applied to the right nerve, or 

 that of the limb protected from the action of physostigma, produced active muscular contrac- 

 tions. The muscles of the tied limb were pale as contrasted with those to which the poison had 

 access, and the latter were distinctly blue in colour. The non-poisoned muscles continued 

 active until forty hours ; but when examined at forty-nine hours they were acid and stiff, and 

 did not contract when galvanised. In the poisoned parts, the functions of the motor nerves 

 were destroyed in three hours and ten minutes ; the non-poisoned, or right, sciatic continued 

 active until thirty-two hours. It was possible to distinguish the heart's impulse on the thoracic 

 walls, and to determine the frequency of its contractions. During the three days that immediately 

 followed the poisoning, these steadily continued at a rate varying from seventeen to twenty-one ; 

 and on exposure, at the end of that time, fifteen feeble beats per minute were occurring. Soon 

 after, the usual irregularities were observed, but the circulation was maintained until eighty- 

 two hours after the injection of physostigma, as the microscope demonstrated. During all this 

 period, the muscles everywhere, except in the tied limb, were flaccid, blue and of alkaline reac- 



