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REPORT OF MEDICAL SECTION. 161 
cumstances which can only affect the venous current. Thus it 
may be arrested or diminished by pressure on the vein above, 
by the horizontal posture or hanging down the head, and by 
forced efforts to expire with the glottis closed. It may be restored 
in increased degree by suddenly desisting from any of these acts 
or circumstances. The occasional pulsatory or remittent cha- 
racter of this sound seems to depend on the momentary increase 
of pressure caused by each pulse of the neighbouring artery ; 
and when, as sometimes happens, these pulses are attended with 
a whizzing, this is in a measure incorporated with the venous 
sound, and increases the periodic swell. The size and down- 
ward current of the jugular veins peculiarly adapt them for 
the production of sound, but probably sounds may be pro- 
duced in most other large veins when circumstances accele- 
rate the current through them. The Committee have detected 
an obscure murmur in some of the large superficial veins of 
the arm and thigh. This murmur is not in pulses, and is to 
be distinguished from muscular sounds by its being confined to 
the situation of the veins, and its being immediately arrested by 
pressure on the vein. Occasionally a pretty Joud murmur or 
fremitus is to be heard on either side of the upper portion of 
the sternum, which, from its resemblance in character to the ve- 
nous sounds, may be supposed to have its seat in the large ve- 
nous trunks that lie underneath. 
Although it appears from these facts that the venous sounds 
_are not necessarily signs of disease, yet the circumstance proved 
__ bythe Committee, that water is thrown into sonorous vibrations 
| more readily than a fluid of a more glutinous character, renders it 
| probable that these and other sounds depending on the motion of 
_ liquids in the apparatus of the circulation may be more easily 
_ produced where the blood is thin and deficient in quantity ; and 
__ under these circumstances they may occur in the neck from the 
_ mere pressure of the muscles on the jugular veins. 
__ The Committee had planned several experiments for the 
_ further elucidation of the second part of the inquiry, By what 
changes, functional and structural, does the apparatus of the 
circulation develope the physical causes of the abnormal mur- 
murs and sounds in the various instances m which they are 
known to occur? This part of the inquiry, so important for the 
_ elucidation of several obscure points in pathology, diagnosis and 
. practice, the Committee propose to resume, if the Association 
_ should think proper to recommend them to continue their labours. 
ip Signed Cuartes J. B. Wituiams, M.D., F.R.S. 
~~ | R. B. Topp, M.D., Professor of Physiology 
: and Pathology, King’s College, London. 
M 
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VOL. VI. 1837. 
