A clinical introduction to the practice of auscultation, and other modes of physical diagnosis : intended to simplify the study of diseases of the lungs and heart / by H.M. Hughes.

  • Hughes, Henry Marshall, 1805-1858.
Date:
1845
Catalogue details

Licence: Public Domain Mark

Credit: A clinical introduction to the practice of auscultation, and other modes of physical diagnosis : intended to simplify the study of diseases of the lungs and heart / by H.M. Hughes. Source: Wellcome Collection.

Provider: This material has been provided by the Francis A. Countway Library of Medicine, through the Medical Heritage Library. The original may be consulted at the Francis A. Countway Library of Medicine, Harvard Medical School.

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    tion is slow; though immediately the circulation is accelerated, either by physical exertion or by mental emotion, a murmur becomes distinct. Hence, also, it happens, that when the cavities of the heart become greatly distended, in consequence either of the magnitude of the obstruction, or of defective nervous power, the ventricles are fre- quently incapable of acting upon and propelling their contents with sufficient force to produce a murmur. The channel is irregular enough, but the rapidity of the current, and of the resulting vibrations, are not equal to the generation of sound. Hence, likewise, it arises, that when fluid is present to a large amount in the pericardium, the heart may be so oppressed with the accumula- tion upon its exterior, that, though great obstruc- tion exist within, no murmur is produced. Thus it will be often observed that when the obstruction is greatest, the murmur, if even it be heard at all, is very feeble • and that when the obstruction is small, the murmur is very loud; thus also, in persons who, for weeks and months, and even years, have presented notably morbid cardiac sounds, these sounds, if the individuals are not carried off suddenly, very frequently, or perhaps even generally, cease altogether some days before death. The cause of this, as before stated, is either that the heart does not contract with sufficient power, or, if it act forcibly, that it cannot act