1873.] 



Irritability after Systemic Death, 



345 



of muscle to which reference has already been made. The first convulsive 

 action, convulsion of syncope, marks a definite period, when the tension 

 of the heart and therewith of the whole vascular system is reduced to a 

 degree of action well defined and attended with definite phenomena. In 

 this stage the force of the heart is sufficient to move the unconscious 

 muscles, and gradually, if blood be resupplied, to lift them again into the 

 condition for the sudden development of active conscious life. The second 

 excitement, convulsion of death, indicates the period when the passive or 

 lower tension of the muscular power ceases. 



A distinction was here drawn by the author between the muscular 

 condition present during syncope and during death. Syncope, it was 

 urged, means the continued action of the heart at a low tension, from 

 which it can be suddenly raised into full tension with restoration of the 

 powers of life ; death means the cessation of the lowest tension at which 

 the heart can effectively work. 



It was shown that in all the cases of restored animation after apparent 

 death the condition of the heart was that of a muscle acting under the 

 lower degree of tension. In this intermediate stage, between syncope and 

 death, the most striking results were obtainable ; but beyond this stage 

 the methods so successful during it, were practically useless for restoration. 



The experiments of the author for reestablishing artificial respiration, 

 together with artificial circulation, and of these combined with electrical 

 excitation of the nervous centres, were next referred to ; but as they had 

 already formed the subject of a paper read before the Society, they were but 

 briefly dwelt upon. If, continued the author, the question be asked, why, 

 at a certain stage of haemorrhage, there is development of muscular excita- 

 bility, the answer is not difficult. The phenomenon is probably due to 

 an irregularity in the distribution of pow T er between the muscular organ 

 and the nervous centre with which it is connected : the effect is due, 

 that is to say, to a continued nervous irritation applied to the muscle 

 after the resistance of the muscle is impaired, while the cessation of the 

 motion is due to the nervous exhaustion that succeeds. In this first 

 series of changes the voluntary muscles and the voluntary centres are 

 involved ; but the loss of blood continuing, the same series of changes 

 affect in turn and in like order the involuntary muscles and their nervous 

 centres : the result of this is the second convulsion, indicating death, 

 after which there is no further motion except that which belongs to par- 

 ticular parts ; there is no central motion, that is to say, supplying all 

 parts as from a prime source of power, and sustaining all parts from a 

 prime direction of the motion supplied. 



The author described in this place a number of experimental attempts 

 to preserve blood for the purposes of transfusion. He had endeavoured 

 to preserve by slow desiccation of blood ; but had found that when blood 

 was submitted to evaporation, however slowly, an albuminous pellicle 

 formed on the upper surface, exactly as caseine forms on milk, and this 



