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Physiology. "About tin independence of the electrocardiogram 



with regard /<> the form-cardiogram." By A. K. M. Notons, 

 assistant in the Physiol. Lai», at Utrecht. (Communicated by 

 Prof. II. Zwaardemaker). 



Principally by the investigations of Engelmann ') and Mahchand j ) 

 the electromotive phenomena which show themselves in every con- 

 tracting heart and which we now register in the electrocardiogram, 

 have heen reduced to manifestations of the changed current of action 

 that can be produced in every muscular tissue by direct or indirect 

 stimulation of the muscular elements. 



Contraction being usually considered as the only visible mani- 

 festation of muscular stimulation and action, the electric phenomenon 

 is involuntarily thought to he connected with the process of con- 

 traction. On theoretical grounds, however, Biedermann') deemed it 

 quite possible, "das/, eine Muskelstelle erregt ist und daher sich 

 negativ zu benachbarten, ruhenden Stellen verhalt, ohne dabei in 

 merklichem Grade contrahirt zu sein." In these theoretical conside- 

 rations lies the nucleus of my investigations. Now the experiment 

 teaches that these conceptions are in accordance with reality. 



Already in my dissertation 4 ) 1 have, in consequence of some 

 experiments, pronounced the supposition that the electric phenomenon 

 in the contracting- heart represents a process by itself, which is borne 

 out by the following experiments. 



The heart of an Anodonta Huviatilis, laid bare, is in its natural 

 position by moans of the unpolarizable magazine-electrodes conducted 

 to the string-galvanometer. (The electrodes with their cottonseeds 

 have previously been put in fresh water for a quarter of an hour 

 and subsequently in the pericard-liquor of the mussel). 



The string-galvanometer of Einthoven with permanent magnet 

 (Edelmann's small model) is (ed by a current of 4 volt with moderate 

 string-tension (38 out of 60 dividing lines). The movements of the 

 heart are registered by a little lexer with a small fulcrum and by 

 a bit of straw placed vertically on the axis, which throws a silhouette 

 on the chink of the registrating apparatus. The registration takes 

 place by means of photography. 



As appears from the first halt' of tig. J the heart shows regular 

 contractions, attended by electric oscillations, which begin a little earlier. 



') Engelmann, Pflüuer's Arcbiv, Bd. XVII, 1878. 



8 ) Mahchand, Pflüükh*s Archiv, Fid XVI 1877 and XVII 1878. 



3 ) Biederhann VS., Elektropliysiologie, Jena 1895, page d-2*J. 



*) Noyons A. K. M. Proefschrift: Over deo uniolonus der spieren, Utrecht 1908 



