156 SEVENTH REPORT—1837. 
of various muscles immediately after death. The sound produced 
in the latter case, in nature and frequency, closely resembled the 
first sound of the heart of the foetus, or of small animals. 
In investigating the morbid sounds of the heart, the atten- 
tion of the Committee has been chiefly directed to the causes of 
those remarkable and various phenomena called murmurs, which 
are either added to, or supersede the natural sounds of the heart, 
and which were happily compared by ZLaennec to the familiar 
noises of blowing, filing, rasping, sawing, purring, cooing, &c. 
This inquiry consists of two parts: 1. What is the essential 
physical cause of the phenomena in question ? and 2. How does 
the apparatus of the circulation develope this cause in the various 
instances in which these phenomena are known to occur? To 
the first of these questions the experiments of the Committee 
supply what they trust will be deemed a satisfactory answer. 
The second is to be fully answered by extensive clinical and 
pathological observation, rather than by direct experiment ; and 
although a few physiological illustrations will be cited to this 
point, yet the Committee do not profess to do more than to open 
this inquiry to allthose who have the means of pursuing it. 
Experiments on the production of sound by the motion of water 
through tubes. 
A Caoutchouc tube, eighteen inches long, and three-eighths of 
an inch in diameter, was attached to the stop-cock of a reservoir 
in which there was water to the depth of eight or ten inches. 
When the water flowed unimpeded through this tube (all 
the air being first expelled,* and the lower end of the tube kept 
under water in a vessel below) no sound was heard ; but on press- 
ing any part of the tube so as to diminish its caliber, a blowing 
sound was heard, at and below the point of pressure, and this sound 
became louder and more whizzing as the pressure was increased. 
The loudest sounds were obtained at the lowest end of the tube, 
where they were sometimes quite musical ; and by increasing the 
pressure or the current at regular intervals, a periodic increase 
and raising of the sound were produced, closely resembling the 
murmur sometimes heard in the neck, to which the French have 
given the name of “ bruit de diable.” 
_ A pin being stuck transversely through the tube, a slight blow- 
ing was heard ; which was made louder on substituting for the pin 
a bit of split goose-quill. A stronger blowing was produced by 
a double thread across the diameter of the tube, especially when 
* As long as any air remains in the tube, aloud crepitation accompanies the 
current. 
