A critical analysis of the memoir read by Dr. Barry before the Academy of Sciences : on the 8th of June, 1825, at the Institute of France, on atmospheric pressure; being the principal cause of the progression of the blood in the veins. / By Henry Searle.

  • Searle, Henry, active 1827.
Date:
1827
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Licence: Public Domain Mark

Credit: A critical analysis of the memoir read by Dr. Barry before the Academy of Sciences : on the 8th of June, 1825, at the Institute of France, on atmospheric pressure; being the principal cause of the progression of the blood in the veins. / By Henry Searle. Source: Wellcome Collection.

Provider: This material has been provided by King’s College London. The original may be consulted at King’s College London.

    18/108 (page 2)
    Secondly.—The comparative velocity with which it is moved through the veins, and through the arteries. Thirdly.—That the constant supply of blood to the heart, cannot depend solely upon the causes to which it has been hitherto ascribed.” Dr. Barry commences, in page 2, by an enquiry What is the amount of all that has been hitherto proved, relative to the circulation of the blood ? ” In allusion to Harvey’s idea, that the heart was the sole power engaged in this function, he says: Later physiologists have done but little to show either the truth or the error of Harvey’s assertions. They have merely admitted a few secondary sources of impulse to the blood; such as,—1. The contractile power of the arteries, whether the effect of muscular or elastic fibres. 2. The insensible contraction of the capillaries, supposed to be independent of the heart. 3. The action of the veins themselves upon their contents. 4. The pressure of muscles of voluntary and in- voluntary motion. Of these supposed powers, some are so little