Researches, critical and experimental, on the capillary circulation / by Bennet Dowler.

  • Bennet Dowler
Date:
1849
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Licence: Public Domain Mark

Credit: Researches, critical and experimental, on the capillary circulation / by Bennet Dowler. 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.

    12/44 (page 6)
    pliysiolon-y of the rod coloring matter of the l)lood, writes with a]ipii^ rent ijood faith, many passages like the toUowing ; '' The coloring matter is normally enclosed in a sac or cell composed of a thin membrane, consisting chiefly of protein, and capable of admit- ting of percolation through its wails Under certain circumstances, although It generally retains the colored fluid it encloses sufficiently firmly to prevent its admixture with the serum. Within the sac is a nucleus of similar chemical composition to the membrane, and the whole thus organized constitutes the blood-disk, globule, or rf^d particle : The bright red corpuscules are always biconcave: in the dark-red blood, the corpuscules are conoex, and the enveloping membrane is ?nuch thinaer ; they readily burst, pi-oduce exosiliosis, emptying the sack, &c. &c. : Oil I'eaching the tapillaries, the coating of oxyprotein is removed, the protein being emplcyed for the repair of tissue, and the oxygen used for efiecting the metamorphosis of efiete and exhausted structures. The corpuscules losing their opaque, covering, have their power of reflecting li-^ht diminished, their concave surfaces are lost, and the whole assumes a venous tint. (N. Y. Jour. Med, and Lond. Med. Gaz. 1845.) Mr. G. Newport, in a paper read before the Royal Society, undertakes to define the corpuscules of insects, and other invei'tebrata, comparing them with those of man, and the vertebrata : He says in the articu- lata the forms are first, the molecules; secondly, the nucleated or oal- shaped corpuscle; thirdly, the spherules, or minute rounded bodies devel- oped from the oat-shaped corpuscle, analogous to the free nucleoli v ^ Valtentin ; and lastly, the discs, which are further developements of the spherules, and analogous to the true i-ed-blood-discs of the higher ani- mals. (Bullet. Med.' Sci. 1845.) No single description (of the red globulus of the blood) has tallied with that which went before. Leeuwenhoeck believed that he saw them consisting each o^ six icell compacted smaller globules. Hewson belie- ved that they were Madders w4iich had within them some central body, loose and moveable ; that often the central part might be seen rolling in its bag, &c. The Abbe Torre, said that these were not globules, hviirings.' (Bell's Anat. and Phys.) Dr. Carpenter calls the globules, ^'■jlatlened discs having a circular form. (Phys. §570.) Sir Charles Bell relies on the microscopic examination of the frog's foot, for the proof of the capillary vessels. He says, naively enough : We do not discover the coats of the vessels, but concltide that they exist, from the confined and certain course of the particles (of blood) which are in motion. (Anat ii. 26). Micography envisages much which seems For man's illusion given. Thus a convex or a concave surface may under certain circumstances appear globular. The different elements of the blood, as air, water, fibrin, fatty matter, albumen, not to mention their probable form, possess- ing as they do, ciifTerent degrees of transparency, difl'erent densities, different degrees of shading power, ofirisation, and more than all, differ- ent degrees of refracting fiirce, would all conspire to throw doubt upon the anatomical accuracy of these microscopic membranes, and (central nuclei, and the conf]gura.tions which are too confidently proclaimed as absolutely characterizing the globules. St-jll more. Physical capillarity