298 PHYSIOLOGY CHAP. 



might exert a toxic action upon the cells of the myocardium. The 

 beneficial effects of adding lime salts to the haemolytic fluid may 

 be explained by the antagonism between the salts of calcium and 

 potassium. 



Bachmann (1906), under Oehrwall's direction, carried out a 

 fresh series of researches upon the action on the isolated 

 mammalian heart of the organic nitrogenous substances present 

 in normal blood, adding it in known doses to Locke's solution, 

 and perfusing it by Langendorff's method. He studied the action 

 of urea, of ammonium carbonate, of sodic hippurate, of sodic 

 urate, of creatine, of hypoxanthine, of xanthine, of allantoin. 

 Generally speaking, he found that these substances, in doses 

 approximately equal to their proportions in normal blood, 

 exercised only a slight and parallel action upon the heart, in- 

 creasing the amplitude of the systole. Some of them further 

 accelerated the frequency of rhythm, in particular urea, which 

 agrees completely with the results of Baglioni. 



Special mention must be made of the recent attempts to 

 revive the dead heart of warm-blooded animals. Kuliabko 

 (1901-3) was the first to revive the heart of animals three or four 

 days after death (the bodies being kept meantime in ice), by 

 perfusing the coronaries with Einger- Locke solution. Seven 

 days after death it was found impossible to revive the normal 

 pulsations of the whole heart ; fibrillary contractions could, how- 

 ever, be observed in the auricles. The heart of an infant that 

 had died of pneumonia was made to beat again after twenty hours. J 



H. E. Hering continued the researches of Kuliabko on the 

 hearts of rabbit, cat, and monkey. In a monkey found dead in 

 the laboratory he succeeded, four and a half hours later, in 

 reviving the heart, left in situ. The body was then frozen. On 

 the following day, i.e. 24 hours and 32 minutes after the animal 

 had been found dead, the heart was revived for the second time. 

 The carcase was again frozen, and a third revival successfully 

 attempted 53 hours and 43 minutes after. 



The same experiments of revival were attempted on the 

 human adult heart. Dencke and Adam succeeded in obtaining 

 pulsations in the heart of a criminal forty-three years old, 13 

 minutes after his execution. 



More recently Hering succeeded, with Einger's solution alone, 

 in reviving the heart of a young criminal of thirty-five, eleven 

 hours after death, and was able to use it for experiment for 

 three hours. It is interesting to note that both Dencke and 

 Hering assert that they found no difference between the human 

 and other mammalian hearts as regards their reaction to circulating 

 fluids. 



TT^-The most generally noted and recognised fact is that the 

 conditions of rhythmical cardiac activity are located in the 



