The first lines of the practice of surgery: designed as an introduction for students, and a concise book of reference for practitioners (Volume 1).
- Samuel Cooper
- Date:
- 1822
Licence: Public Domain Mark
Credit: The first lines of the practice of surgery: designed as an introduction for students, and a concise book of reference for practitioners (Volume 1). 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.)
47/738
![incubated egg; inasmuch as at first merely tubes for the blood can be discerned, but nothing like regular vessels.* Mr. Hunter injected a thigh-stump through the femoral artery, and thus filled the mass of coagulating lymph, which Lay on the surface, and which was found to be cellular, and not composed of regular vessels. But, as Meckel observes, Wolflft had already pointed out, what was remarked by Hun- ter, that in the beginning at the circumference of the embryo chicken, a circle of small specks of blood was produced, which soon changed into a vascular structure; though the sides of this new texture were not differernt from the substance in its circumference. Nay, says Meckel, the immortal Harvey proved, in opposition to former tenets, that the blood must be the first formed part, as the vessels only serve for its cir- culation.:]; Meckel thinks it probable, that, in certain states of inflammation, contractile cavities, which communicate to- gether, are first formed in the coagulating lymph, the blood running through them in rjo determinate direction, as in the lower animals ; but that they afterwards change into true vessels, which at length anastomose with the old ones. The form of the new vessels is said to be very simple, hi all the instances, in which Meckel examined those between th,e pleura and ribs, he found them quite straight, even.when nearly an inch in length. He describes them as having sometimes ramifications only at their two extremities, so as to resemble in miniature the vena portarum system ; or a distinct new system of vessels, with a middle trunk, and no heart. The new vessels, he says, usually lie very close to- gether, and the ramifications at each end probably soon dis- appear after the establishment of anastomoses between the old and new vessels.§ Whatever may be the situation of inflammation, it i» always most violent on the side nearest to the external surface of the body. This very curious fact, which was first pointed out by Mr. Hunter, is so constant, that it may be regarded as a sort of law in the animal economy. *B.2.abth 2. p. 33. t Wolff, De Generations Hal. 1759. p. 197. t Harveius, De Generat. p. 64. 190. 256. § See Meckel's Handbuch der Pathologischen Anatomie, b. 2. abth. 2. p. 33—35](https://iiif.wellcomecollection.org/image/b21110785_0047.jp2/full/800%2C/0/default.jpg)
