88 ANALYTIC SECT. IX. 
heart,” says this author, “ the alternate contrac- 
tions of the ventricles and auricles, examined by 
the aid of the stethoscope, and touching the pulse 
at the same time, present the following pheno- 
mena: The moment the artery strikes the finger, 
the ear is gently raised by a movement of the 
heart isochronous with that of the artery, and 
accompanied by a dull yet distinct sound. This 
phenomenon is owing to the contraction of the 
ventricles. Immediately after, and without any 
intermission, a sharper sound like the lapping of 
a dog, announces the contraction of the auricles.” 
This is what Laennec calls the rythm of the heart, 
a knowledge of which is extremely useful in the 
diagnosticks of diseases of this organ. 
ccv. As the state of the pulse depends essen- 
tially on the expansion of the cardiac cavities, 
it is necessarily diversified by an infinity of con- 
tingent circumstances. Generally speaking, how- 
ever, the pulse is full and strong in all inflamma- 
tory diseases, but small and weak in fevers of the 
typhoid type. But the sympathy of the heart 
with the other important organs, is not uniform, 
for in inflammation of the abdominal viscera, the 
pulse is never so full as in pneumonia or pleuritis, 
There is also a depression of the pulse from 
excessive inflammation and congestions of blood, 
which is extremely embarrassing to the half- 
educated practitioner. 

