14 QUATERCENTENARY STUDIES IN PATHOLOGY 



restore the auricle to regular contraction in persistent fibrillation — and 

 this is not successful except occasionally — is by the application of cold 

 directly to the heart. Large quantities of chilled salt solution poured on 

 the exposed heart sometimes restores it to regular contraction. 



The auricular delirium, which we have described as occurring in dogs 

 during the operation, was obviously the result of sensory stimuli carried 

 from the chest wall to the central nervous system. This might affect the 

 heart either by inducing changes in the blood pressure (shock) or by nervous 



Fig. 6. — Tracings (Hurthle's tonometer) from the carotid of a dog. From ^ to .5 in the 

 lowest tracing the auricle was stimulated with a very weak tetanising current, and imperfect 

 fibrillation resulted at intervals. From B onwards, the stimulation ceased. In the middle 

 tracing a stronger series of shocks was applied to the auricle at C, and it immediately passed into 

 fibrillation. The highest tracing was taken during prolonged fibrillation from auricular stimulation. 



impulses passing along the cardiac nerves to the heart. In the descrip- 

 tions of shock given in surgical textbooks, the heart is often said to be 

 irregular, but personal enquiry among our surgical friends failed to elicit 

 any information in regard to the character of the irregularities, and we 

 were led to the conclusion that cardiac irregularity in shock is extremely 



(108) 



