Prize dissertations on inflammation of the periosteum, eneuresis irritata, cutaneous diseases, cancer of the breast, malaria / by Usher Parsons.

  • Parsons, Usher, 1788-1868.
Date:
1849
Catalogue details

Licence: Public Domain Mark

Credit: Prize dissertations on inflammation of the periosteum, eneuresis irritata, cutaneous diseases, cancer of the breast, malaria / by Usher Parsons. 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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    two months after, an osseous swelling of considerable magnitude was formed around the foreign body. Every time, says Mr. Cruveilhier, that I have seen the periosteum in contact with pus, I have never known ossification to take place; and surgeons have long since observed, that pus or blood interposed would effectually prevent a reunion of detached peri- osteum, so as to prevent exfoliation. How is this phenomenon to be explained? I think it may be done by considering the nature of the process of ossification. Thus, when the periosteum is separated from a dead bone, it retains its attachment to the heads or articulating ends of the bone. These swell and soften, and continue to retain between them the sequestrum or mortified bone. The periosteum thus detached, swells and secretes from its internal face a small quantity of reddened fluid, at first very thin, like moisture bedewing the membrane. Its quantity and consistence gradually increase till that which wTas a limpid fluid becomes a jelly, which thickens daily and passes into a state of cartilage. In this, osseous fibres are deposited, and finally the fluid and cartilaginous substance disappear, leaving the new bone perfectly formed. Now, while pus or blood are lodged between the bone and detached periosteum, the very thin fluid secreted from the latter to form cartilage and bone mixes with the blood or pus, instead of congealing and ossifying, as it does where, in place of such fluids, flakes of bone or metallic substances are interposed. The foregoing experiments establish satisfactorily the nature of the office of the periosteum in the cure of superficial necrosis. No one can conclude other-