CHAP, xiii.] CIRCULATION. 205 



.there is in the embryon the smallest trace of nervous system, 

 and at a later period, in the adult, when the motory nervous 

 system is killed by the help of the poison curare, the heart 

 continues nevertheless to palpitate. It is even totally freed 

 from dependence on the nervous centres, and we no longer 

 succeed, as in the heart's normal state, in suspending the 

 cardiacal beatings by irritating one of the principal sources 

 of the heart, the pneumogastric nerve. 1 



In effect, in the state of integrity of the organism, the 

 heart, spite of its independence, is bound by its nervous system 

 ; to the rest of the organism, and specially to the brain. The 

 rapid ingestion of a very cold drink into the stomach provokes 

 ' & contraction of the vessels of the brain, thence anaemia of 

 , that organ, and sometimes stoppage of the beatings of the 

 i heart, whence death can result. 2 A sudden stoppage of the 

 j beatings of the heart can also be provoked by a shock on the 

 j epigastrium : it is produced when the, heart and the viscera of 

 a frog, being laid bare, we strike a violent blow on the abdominal 

 viscera. 3 A sharp pain on the passage of a sensitive nerve 

 i produces the same effect. 4 If we electrise any nerve whatever 

 i the heart stops in its state of dilatation, in diastole. The 

 ! result is the same in a frog, if we electrise the origin of the 

 I spinal marrow, the medulla oblongata. 5 But the stoppage of 

 | the heart in diastole is produced more surely still if we electrise 

 | the nerves which connect it direct with the brain, the pneumo- 

 gastric nerves. 



Moral impressions produce the same effect. Syncope fre- 

 quently follows a strong emotion. This is a fact of common 

 I observation. Sometimes, on the contrary, emotions provoke a 



' J Saissy, Regnault. See also Gavarret, DCS PMnomZncs Physiques de la, 

 [Tie, p. 227. 



? 2 R. Ganz, Ueber die Gefahr des Jcalten Trunkes bci erhitztcm Kdrper 

 (Pfliiger's Archiv, 1870). 



3 Brown -Sequard, Archives Generate de Mtditine, 1856, t. VIII. 

 I 4 Cl. Bernard, Sur la Physiologic du Cceur. 



6 Vulpian, Legons sur la Physiologic du Systtme Nerveux, p. 853. 



