The principles of midwifery : including the diseases of women and children / by John Burns.

  • Burns, John, 1774-1850.
Date:
1811
Catalogue details

Licence: Public Domain Mark

Credit: The principles of midwifery : including the diseases of women and children / by John Burns. Source: Wellcome Collection.

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

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    formed at once, but in parts, and is not completed before the fifth month ; even then, it differs in its shape from the ear after birth. It is at first like a gently depressed circle. The extremities early appear like the buds of a plant. The arms are directed obliquely forward, toward the face, and are larger than the inferior extremities. The genitals, for a time, are scarcely to be observed; but in the third month, they are large in proportion to the body. The foetus does not grow in an uniform ratio, but, as has been observed, by the learned anatomist, Dr Soemmering, the increment is quicker in the third than in the second month. In the beginning of the fourth it becomes slower, and continues so until the middle of that month, when it is again accelerated. In the sixth month, it is once more re- tarded, and the progression remains slow during the rest of gestation. • The proportion between the weight of the foetus and its involucra, is reversed at the beginning and the end of ges- tation. When the embryo does not weigh more than a scruple, the membranes are as large as- a small egg. Even when the foetus is not larger than a fly, the membranes re- semble, in shape and size, a large chesnut. On the other hand, at the full time, when the foetus weighs seven pounds, the placenta and membranes do not weigh a pound and a half, and the proportion of liquor amnii is greatly lessened. In the twelfth week, the foetus weighs nearly two ounces, and measures, when stretched out, about threexinches. The membranes are larger than a goose's egg, and weigh, if we include the liquor amnii, • several ounces. In the fourth month, the foetus is about five inches long. In the fifth month, it measures six or seven inches. In the sixth month, the foetus is perfect and well formed, measures eight or nine inches, and weighs about one pound troy ; whilst the pla- centa and membranes weigh about half a pound, exclusive of the liquor amnii. The foetus is now so vigorous in its action, that there have been instances, though most rare, of its continuing to live, if born at so premature a pe- riod. In the seventh month, it has gained about three in-