Volume 2

The study of medicine. Containing all the author's ... improvements / [John Mason Good].

  • Good, John Mason, 1764-1827.
Date:
1829
Catalogue details

Licence: Public Domain Mark

Credit: The study of medicine. Containing all the author's ... improvements / [John Mason Good]. Source: Wellcome Collection.

    16/724 (page 6)
    I. Ma- chinery of the san- guineous system. arteries. expression is, one or two facts, brought to light by dis- section, have materially weakened, if not quite subverted the hypothesis. A few instances have occurred of the heart being found without any pericardium whatever, or any device to answer its purpose. Dr. Baillie has re- corded a singular instance of this in a man, aged about forty, who died of an accidental complaint, without seeming to have suffered from the deficiency*. -Many examples are met with, where the bag of the pericardium and its reflected layer on the heart are completely adherent together, without any particular effect on the action of the latter viscus. A similar case to that in Dr. Baillie’s works, is reported by M. Littre}. The circumstances which have most influence in fixing this organ are, its situation between the two lungs, which enclose it nearly on every side; and its connexion with the large blood vessels. When, as an able physiologist has observed, we take into consideration the relative importance of the heart and brain, as far as regards mere animal existence, we shall be led to decide in favour of the former. In incubation, as the immortal Harvey pointed out, a beating point, a “punctum saliens,” as he expresses it, which is the rudiment of the future heart, precedes the formation of other parts of the body, and is visible for some time before any trace of the brain can be distinguished. Acephalous fcetuses have been known to attain their full size in the womb, and even to have lived for a short time after birth, and then died from not being able to effect those changes, which are incidentally necessary to an ex- istence of any duration. For example, a regular supply of nutritious matter is essential to the support of life ; this can only be supplied by the introduction of food into the ~ stomach by the act of deglutition; but this act, at least in the higher animals, cannot be performed without the intervention of the nervous system {. The sides of arteries are divisible into several strata of dissimilar substances, technically named coats or tunics. Mascagni, like the older anatomists, who preceded him, * See Baillie’s Works, by Wardrop, vol. i. p. 44. + Hist. de Acad. des Sciences, 1712; p. 37. + See Bostock’s Physiology, vol. i. p. 335.