ON THE MOTIONS AND SOUNDS OF THE HEART. 203 
The end of the instrument was placed in mediate contact 
with the abdominal parietes, and held firmly down upon the 
surface, with the intervention of a shirt and thick flannel 
under-vest; a strong and sudden expiratory effort was then 
made (in the manner described in the First Report of the 
London Committee) with the mouth and nostrils closed, so 
that a strong vibratory action, ending in firm tension of parietal 
muscles, was sensible to the subject of observation (the Re- 
porter), and likewise to the observers, and with this result, 
that a single loud, obtuse, abrupt, short sound was heard, and 
thought by every gentleman to resemble, more or less, the 
systolic sound of the heart. 
S. 2. The same experiment was repeated, with the addition 
of several folds of a silk handkerchief to the intervening sub- 
stances; and again, with a double fold of cloth and silk like- 
wise, in addition to the under-clothing above named, but 
without any important difference of result. 
S. 5. Hard substances also were interposed above the 
under-clothing, viz. a common framed school slate, and small 
bound books of different sizes; but no important difference 
was observed, except with the slate, through which the sound 
was considered to be decidedly less distinct than in any other 
form in which the experiment had been tried. In all these 
trials pains were taken to keep the cup of the stethoscope in 
accurate contact all round, through the substances interposed 
with the abdomen; and that was easily effected by the use on 
the part of the Reporter, who was the subject of experiment, 
of both hands at once in maintaining equable pressure. 
It is proper to mention, that several observers agreed in 
stating that similar sounds occurring to show in the cardiac 
i _ region, would be referred by them to the systole of the heart 
without any hesitation. 
_ Conctusions rrom BoTH SERIES For 1838-39 anv 1839-40. 
| 
Motions. 
| : Ist. That the order of the motions of the auricles and 
| ventricles is by continuous succession rather than by alter- 
nation of actions. The auricles contract abruptly after the 
Rest or pause, and the ventricles immediately after the auricles, 
without any distinct interval between the successive systoles. 
And the diastoles of the cavities follow in somewhat similar 
