A popular cyclopedia of modern domestic medicine : comprising every recent improvement in medical knowledge : with a plain account of the medicines in common use / by Keith Imray.

  • Imray, Keith.
Date:
1849
Catalogue details

Licence: Public Domain Mark

Credit: A popular cyclopedia of modern domestic medicine : comprising every recent improvement in medical knowledge : with a plain account of the medicines in common use / by Keith Imray. 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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    character. This cartilage is not, as was erroneously supposed, hardened into bone; but is absorbed and carried away by one set of vessels, while another set is employed in depositing, in its room, matter for forming the new bones. This process is effected in the following manner. The transparent vessels of the cartilage first begin to dilate to re- ceive the red blood ; at this time an artery can be observed penetrating towards the middle of the bone; this artery is soon accompanied by others, all forming a sort of net-work, and conveying red blood; and now ossification may be said to have commenced. Gradually the cartilage grows opaque and brittle, and will no longer bend. The bony centre spreads according to the dimensions of the bone; and may be known by its hard feel, when examined by a sharp instru- ment ; similar points of ossification are now found and in a like manner, in other parts of the bone, till its whole body becomes opaque ; and now the vessels, stretching from the centre towards the extremi- ties, having penetrated the cartilages which separate the heads from the body of the bone, enter these heads, when ossification commences here also. From this mode of process it will be seen, that the heads and body are at first distinct bones, formed separately and connected only by cartilage, arifl they are not united till the age of eighteen or twenty years. Thus the formation of bone is effected by the action of its blood vessels, which may be seen entering in one great trunk into the body of each bone, and spreading thence towards both extremities. It is by this action all the parts of the body are evolved ; it forms the blood as is seen in the case of the chick, which has no other way of receiv- ing this fluid but by forming it within its own body; and from the blood are all the solids constructed, by the same action of the vessels. All animals have the power of assimilating their food, and with the assistance of air, of converting it into blood ; and as by the action of their larger vessels they can thus elaborate fresh supplies of red blood, so the action of particular vessels is intended to prepare particular parts. Thus some add to the solids to assist growth, others for sup- plying the continual waste; while more are employed in effecting the different secretions within the body, one of which is the forma- tion of bone. In this manner then is ossification accomplished ; the arteries of the transparent cartilage of the foetus, beginning at length to receive the red blood, commence their deposition of earthy matter. This at first appears in numerous specks, which spreading, afterwards meet, and at last constitute perfect bone. But, while these arteries are thus employed in depositing bone, there are other vessels, (called absorbents, from the nature of their function) busily engaged in re-