Compendious system of midwifery : chiefly designed to facilitate the inquiries.

  • William Potts Dewees
Date:
1824
Catalogue details

Licence: Public Domain Mark

Credit: Compendious system of midwifery : chiefly designed to facilitate the inquiries. Source: Wellcome Collection.

Provider: This material has been provided by the University of Massachusetts Medical School, Lamar Soutter Library, through the Medical Heritage Library. The original may be consulted at the Lamar Soutter Library at the University of Massachusetts Medical School.

    23/628 (page 17)
    position, as it acts in some measure as a key-stone does to an arch ; this arises from two circumstances of form: the anterior part of the bone is broader than the posterior, consequently enters like a wedge between the ossa innominata ; this enables it to sustain without injury any force that may operate from within, outwards : the superior portion is also broader than the inferior, and of course is placed precisely analogous to the key- stone of an arch, by which it is enabled to support without yielding to the superincumbent weight of the body, &c. We cannot fail to remark how admirably this arrangement gives stability to the whole of the pelvic circle. 5. The union of the last lumbar vertebra with the base of the sacrum, is permitted to take place in such manner as to look over and into the superior opening of the pelvis, so as to form a promontory, and hence is called the projection of the sacrum. 6. The length of this bone is usually from four inches to four and a half, its breadth is about four inches. Its thickness, if mea- sured from the middle of its base anteriorly to the extremity of the superior spinous tubercle on its posterior face, is very con- stantly two inches and a half; and we are informed by Baude- locque,* that this measurement is so constant, that he did not find it vary a line in between thirty and forty pelves, the greater part of which were deformed. The concave form of this bone gives a hollowness to the greater part of its length ; the depth of this in a well-formed bone is about half an inch. Sect. III.— The Coccix. 7. This addendum to the sacrum is also of a pyramidal form, and about an inch and a quarter in length; like the sacrum itself, it is an inverted pyramid, its base being united with this bone by intervening cartilage: it is formed of three bony por- tions, whose connection with each other is readily observed by * System, page 18, par, 35. [3]