A manual of clinical diagnosis by means of microscopic and chemical methods : for students, hospital physicians, and practitioners / by Charles E. Simon.

  • Simon, Charles E. (Charles Edmund), 1866-1927.
Date:
1897
Catalogue details

Licence: Public Domain Mark

Credit: A manual of clinical diagnosis by means of microscopic and chemical methods : for students, hospital physicians, and practitioners / by Charles E. Simon. Source: Wellcome Collection.

    36/620 (page 28)
    In addition to the substances mentioned, tlie following are also found in the blood: Fat occuu-s in an amount varying from 1 to 7 p, m. in fasting animals, while following the ingestion of a meal rich in fats as much as ]2.5 p. m. has been encountered. Soaps, cholesterin, and lecithin have likewise been found. Sugar, probably glucose, appears to form a normal constituent of the plasma, amounting to 1 to 1.5 p. m. in man. While it is pos- sible to increase this amount to a certain degree by the ingestion of large quantities of sugar, this appears in the urine, according to Claude Bernard, as soon as 3 p. m. has been exceeded. In addi- tion to ghacose another redncing-substance has been found in the blood, which differs from the former in not being fermentable. Among the extractives which have been found there may be mentioned: urea, uric acid, kreatin, carbamic acid, sarco-lactic acid, glycogen, and hippuric acid,and under pathologic conditions xanthin, hypoxanthin, paraxanthin, adenine, guanine, leuciu, tyrosin, lactic acid, cellidose, /?-oxybutyric acid, acetone, and biliary constituents. It has been pointed out that the color of the blood is referable to the presence of htemoglobin contained in the red corpuscles, and also that the color varies from a bright scarlet-red in the arteries to a dark bluish-red in the veins, the exact shade depending upon the amount of oxygen present in combination with haemoglobin as oxyhsemoglobiu. Upon chemical examination two other gases may be demonstrated under physiologic conditions, viz., carbon dioxide and nitrogen. Of these the latter appears to play no part in the body-economy, and the amount present merely corresponds to that which would be absorbed by an equal volume of distilled water, viz., 1.8 vol. p. c, calculated at 0° C. and 760 Hgmm. pi-essure. The amount of oxygen and carbon dioxide, on the other hand, undergoes considerable variation, depending upon the particidar bloodvessel from which the specimen is taken—i. e., whether this be an artery or a vein, and, furthermore, upon the velocity of the blood-ciirrent, the temperature of the body, rest, exercise, etc. The relation existing between the amounts of these gases in arte- ries and veins may be seen from the following table: Arterial blood. Venous blood. Oxygen .... 21.6 per cent. 6.8 per cent. Carbon dioxide . . . 40.3 48.0 Nitrogen .... 1.8 1.8