A laboratory manual of physiological and pathological chemistry for students in medicine / authorized translation from the 2d revised and enl. German edition by W.R. Orndorff.

  • Salkowski, E. (Ernst Leopold), 1844-1923.
Date:
1904
Catalogue details

Licence: In copyright

Credit: A laboratory manual of physiological and pathological chemistry for students in medicine / authorized translation from the 2d revised and enl. German edition by W.R. Orndorff. Source: Wellcome Collection.

    48/304 (page 32)
    Digest für two to tlirec days at 40°, sbaking repeatedly and tlior- ouglily, tlien filter and drain the residuc conipletely by pressure. Heat tlie extract in order to coagulate tlie all)umin, evaporate the filtrate to aboiit 500 cc., make strongly alkaline with ammonia, and ])recipitate ^\'ith ammoniacal silver solution, etc. By means of the digestion the nuclein is decomposed and the substances which prevent the precipitation of the hypoxanthine silver are removed. V. Detection of Organically Combined Phosphorus in Meat Extract. According to Siegfried, meat extract free from albumin contains an organic substance (nucleon) in which phosphorus is present. Carniferrin is the name given by Siegfried to the iron compound of this substance. The following method may be used for the preparation of this compound: Dissolve 10 g. of meat extract in 200 cc. of water, make faintly alka- line with ammonia, add calcium chloride solution as long as a precipitate forms (the reaction must remain neutral during the precipitation and later a little more ammonia is to be added), and filter. To the filtrate add 15 cc. of a 3 per cent. ferric chloride solution, heat to boiling and, if necessary, neutralize exactly with ammonia. The precipitate is fil- tered off and washed. It dissolves in dilute sodium car- bonate solution, forming a more or less clear solution. The remainder of the carniferrin is ground with alcohol, filtered, and then treated with a small quantity of ether. The pres- ence of the phosphorus may be shown by fusing with the oxidizing mixture, dissolving the fused mass in water, filter- ing from the iron oxide, and testing for phosphoric acid in the filtrate.