Lectures on the blood and on the changes which it undergoes during disease : delivered at the College of France in 1837-8 / by F. Magendie.

  • Magendie, François, 1783-1855.
Date:
1839
Catalogue details

Licence: Public Domain Mark

Credit: Lectures on the blood and on the changes which it undergoes during disease : delivered at the College of France in 1837-8 / by F. Magendie. Source: Wellcome Collection.

Provider: This material has been provided by the National Library of Medicine (U.S.), through the Medical Heritage Library. The original may be consulted at the National Library of Medicine (U.S.)

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    I derive much satisfaction from this proof of interest in my labours; I beg its author will accept my thanks, and, at the same time, I would entreat each of you to supply me, from time to time, with specimens of the bleedings you may have occasion to perform, accompanied with an account of the patients on whom they were practised. For my part, from the 1st of January next, I will cause what I call trial bleedings to be regularly practised in my wards. Exact notes of these shall be kept, as well as of the previous and subse- quent condition of the patients. By these means, at the close of the session, we shall have accumulated a large number of facts and observations, which will materially assist us in carrying out the plans we have laid down. You remember, without doubt, the various facts we passed in review at our last meeting. Those facts showed you the import- ance of a close acquaintance with the state and composition of the blood generally, and with such morbid changes as it is liable to undergo. They proved, also, that those changes play an important part in the production of a host of diseases, the causes of which appeared an impenetrable mystery. We have but just entered on the study of the blood; and scarcely had we done so, when we were fortunate enough to discover a phenomenon that had pre- viously escaped the notice of both natural philosophers and medical men. Yet that phenomenon is one indispensable for the persistence of life, inasmuch as without it the circulation of the blood must cease. Heretofore the particular conditions, which enabled the blcod to traverse tubes of scarcely a thousandth part of a millemetre, were unknown. In all probability physiologists considered the matter quite natural, and therefore troubled themselves little about it. We think differently, however, and shall, therefore, continue our inquiry into the properties that confer on the blood that marvellous power. The questions we have so far treated of belong, in great measure, whatever may be said to the contrary, to the subjects of physics and hydraulics. You will find that, in elucidating them, we shall have no occasion to avail ourselves of the so-called contractility of the vessels, which, in reality, does not exist; and we shall be quite as independent of the species of sensibility, termed insensible, and of the entire collection of absurd terms by the help of which no few romances, doubtless very clever, but very empty too, have been got up about the capillary circulation. There is a fact, in physics, remarkable for the excellent term of comparison which it serves to establish between the phenomena of the movement of the blood in our organs and the circulation of liquids in inert tubes. I allude to the enormous pressure which is required in order to make water pass through a tube of very small diameter, while the blood traverses with ease the infinitely more minute tubes that abound in our tissues. There must be