264" SIXTH REPORT— 1836. 



Both Bounds were heard with the instrument applied to the 

 great arteries ; but the sound with impulse or first sound alone 

 was heard on the ventricles. 



The heart could not, the Committee were satisfied, strike 

 against the chest's walls, or any other hard object. 



After opening the pericardium the sounds were weaker ; 

 but both sounds were heard with the slethescope applied to 

 the roots of the great arteries. Both sounds were heard also 

 on the great arteries where a portion of lung was interposed be- 

 tween the instrument and the vessels. 



The heart continued to act for forty minutes. 



Experiment 4. — Subject, a young ass prepared as the last. 

 Death twenty- six minutes after poisoning. 



At the roots of the great arteries the two sounds were di- 

 stinctly heard, but after the introduction of two ciirvedawls into 

 the arteries (for the purpose of hooking up one lamina of each 

 sigmoid valve) the second sound was wanting, the first being 

 still distinct ; on withdrawing the awls two sounds were heard, 

 and soon after the heart ceased to act, twenty minutes after the 

 death of the animal. At each systole while the heart acted 

 vigorously, the ventricles felt to the finger as hard as cartilage. 



The heai-t being cut out and plunged in warm salt and water, 

 a slight undulatory contractile motion pervaded the substance 

 of the ventricles and columns carnefs and contiimed for some 

 time. In this and every other observation the vermicular or 

 undulatory motion supervened upon the cessation of the normal 

 action of the organ, and never before the organ had ceased to 

 act as a whole. 



Experiment 5. — Subject, a donkey seven months old, which 

 expired forty-three minutes after being poisoned with woorara. 



The heart just before death was heard with short loud pulsa- 

 tions ; when the chest was opened, it ceased to beat, and was 

 very much distended with blood. When part of the blood was 

 let out by cutting the pulmonary artery, the ventricles began 

 again to pulsate feebly, but without sound. When the heart 

 was cut out it presented the undulatory motion, which was in- 

 creased by immersion in cold water. The two ventricles being 

 opened by cuts at the apex at right angles to the septum, and the 

 heart being drawn with the apex upwards through water, the 

 laminae of the mitral and tricuspid valves were seen to close to- 

 gether each time the heart was so drawn upwards through the 

 water. 



Experiment 6. — Subject, a young ass destroyed by pithing. 



On opening the chest the heart acted regularly, producing 

 both sounds distinctly : curved awls were then introduced into 



