The practice of surgery : a treatise on surgery for the use of practitioners and students / by Henry R. Wharton ... and B. Farquhar Curtis.

Wharton, Henry R. (Henry Redwood), 1853-1925

Date:: 1902

Credit: The practice of surgery : a treatise on surgery for the use of practitioners and students / by Henry R. Wharton ... and B. Farquhar Curtis. Source: Wellcome Collection.

Provider: This material has been provided by the Augustus C. Long Health Sciences Library at Columbia University and Columbia University Libraries/Information Services, through the Medical Heritage Library. The original may be consulted at the the Augustus C. Long Health Sciences Library at Columbia University and Columbia University.

19/1268 (page 7)

$were in inverse proportion to the amount of inflammation' it excites, the local inflammatory changes appearing to limit the growth of the invading bacteria and to prevent their entrance or the entrance of their toxiues into the circulation. Resistance offered by the Tissues.—The tissues have considerable poAvers of resistance to infection under ordinary circumstances, although the exact sources of this power are not well understood. Phagocytosis, which is the power of destruction and removal of bacteria sup]30sed to be possessed bj^ the leucocytes emigrating from the blood-vessels (as will be described in the chapter on inflammation), explains it in part, but the ma- jority of pathologists are unwilling to give this mode of action the full credit which Oohnheim and Metchnikoff claim for it. It is also partly accounted for by the germicidal prox)erties of blood-serum, which can be compared to that property of the serum by which it dissolves the blood-corpuscles of another animal, as shown by Landois years ago. It has been found that if the serum is gently heated to 131° P. (55° C.) it loses the power of destroy- ing corpuscles and germs, which proves that their destruction is not due merelj to the specific gravity of the serum or to its proportion of inorganic salts, for neither is altered by the heat. It has also been shown (Buchner) that this power is destroyed by adding distilled water to the serum, although it remains intact when the serum is diluted with physiological salt solution (one part sodium chloride to five hundred i)arts water), and can be restored to the serum diluted with plain water by the addition of a sufficient quan- tity of sodium chloride. Certain experiments (Eoger) indicate that there must be some difference between the two actions of the serum in dissolving corpuscles and destroying germs, for it appears that the streptococcus of erysipelas grows as well in the serum of immunized as of normal animals, but that it loses its virulence in the former. These facts make it certain that the germicidal power resides in some proteid body analogous to the antitoxines, to be described below. Bactericidal substances (alexines) are produced by the leucocytes and other cells, and are taken up by the serum, so that the latter is more capable of destroying germs in parts which are the seat of an inflammatory cell-production. The resistance of the tissues may in some cases be due to the absence from them of some particular element necessary to the growth of a particular micro-organism. This refractori- ness varies in every species of animal in its relation to every form of germ, and different individuals of one species also vary in their susceptibility, and even difi'erent parts of the body vary in the same individual. Thus, inoculations of cultures of a certain strength will produce suppuration in the eye but not in the cellular tissue, while stronger ones will act in the latter but not in the peritoneum. The resistance of the human tissues to the pyogenic germs is usually less than that of the lower animals. Any cause which depresses the system, such as exhausting disease, anaemia, diabetes mellitus, arteriosclerosis, alcoholism, obesity, hunger, fatigue, and even exijosure to cold, is apt to favor the growth of germs, although experiments have as yet failed to prove the influence of exposure. The tissues, therefore, are able to destroy bacteria, but in most cases it will be found that there is a definite limit to their resistance, and that if the$