2 4 



Scientific Proceedings (46). 



remain in intact connection with the spinal cord, and if the vessels 

 be anastomosed with those of a dog in tetany, so that the peripheral 

 portions of the normal leg are bathed with tetany blood, the nerves 

 of that leg assume the characteristic hyperexcitability of tetany, 

 and twitchings may even occur. Reestablishment of the con- 

 nection with the normal circulation brings back the excitability 

 to normal. 



From these experiments, it may be concluded that the hyper- 

 excitability is peripheral and is dependent upon some change in 

 the character of the blood. Experiments with curare, to deter- 

 mine whether or not this is an affection of the nerves alone, have 

 not yet been completed, although one has the general impression 

 that the excitability of the muscles themselves is increased over 

 normal. The value of the experiments is thought to lie particu- 

 larly in the opportunity which is offered for the study of tetany 

 blood modified in various ways and used as the fluid for perfusing 

 an isolated extremity. 



7 (626) 



Curves from a case of transient complete heart block, showing 

 constantly varying ventricular complexes. 



By ALFRED E. COHN. 



[From the First Medical Division, Mount Sinai Hospital, 

 New York.] 



The patient from whom the curves were taken has been under 

 observation since August, 1910. He was at that time suffering 

 from cardiac decompensation. It was clear from the physical 

 examination that he had a valvular defect. Combined arterial 

 and venous curves were made. These showed that for short 

 periods every impulse from the auricles was answered by a ven- 

 tricular contraction, while at others the ventricular contractions 

 responded to every second beat of the auricles. Curves were 

 taken in February and March, 191 1. These were volume curves 

 from the jugular vein and radial artery and likewise curves of the 

 cardiac action current, registered with an Edelmann string- 

 galvanometer. At first the ventricles responded to every second 



