ON THE MOTIONS AND SOUNDS OF THE HEART. 195 
sometimes, and without apparent cause, more obtuse than 
others, and more short and abrupt, and the second was often 
wholly wanting or too indistinct for observation. 
S. 2. Further, there was observed a feeble dull sound, very 
short and rapid, synchronous with the left auricular systole, 
and somewhat anterior to the ventricular hardening, and up- 
rising, but scarcely separated by any distinct interval from the 
ventricular sound, and rather continued into it in a manner re- 
sembling the apparent passage of the auricular systole into 
that of the ventricle. 
S. 3. The glass tubes were in this experiment introduced as 
before, with similar results. Nothing striking occurred in that 
passed into the auricle, but a very short column being obtained, 
and that nearly stationary, owing probably to the auricle having 
been penetrated in several places by the hook and screw so as 
to suffer escape more readily by the other orifices. But the 
ventricle gave like results as in the former case, viz. a column 
rising in systole, stationary in diastole, and at length reaching 
the upper end so as to overflow. All the previously observed 
phznomena of the motions of the auricles and ventricles, in 
themselves and with respect to each other, and with respect to 
the pericardium, were confirmed on this subject, so that the 
description of those given under the head of the former expe- 
riment of this day, themselves but repetitions of former obser- 
vations, must be considered to apply to the normal condition 
without any important restriction or qualification. 
OssERVATION XVII. 
July 26th.— Phenomena: Dog—Distension to hardness of 
auricles during a torpid and as it were semi-paralytic state of 
ventricles ;—results of a prick in left auricle ;—proofs of active 
nature of auricular systole, and of negative character of ven- 
tricular and auricular diastole ;—of venous regurgitation du- 
ring auricular systole, and of equal size of both ventricles, &c.; 
—confirmation of other former observations. 
Subject, a Mastiff-terrier eighteen months old, poisoned 
—with prussic acid. 
S. 1. Heart acting regularly but rather feebly, though large 
and muscular; much distended and on both sides equally. 
Left ventricle and auricle both much dilated and the auricle 
quite tense with blood, so that the appendix could not contract 
for some time until a prick was made in it, when a jet was ob- 
served coincident with the systole. Some observers thought 
the jet synchronous with the systole of the ventricle ; but on 
placing the fingers in contact with the sinus and fundus ven- 
o 2 
