56 



208. Mince a small piece of liver from an animal which 

 has been dead for 24 hours. Boil the liver either in water or 

 a saturated solution of sodium sulphate. Filter. The filtrate 

 should not be opalescent. 



209. Test the reaction of the filtrate to litmus paper. 



210. Neutralize a portion of the filtrate with a little so- 

 dium carbonate and filter ; then test with iodine for glycogen. 

 If there is no deep brown mahogany color, glycogen is absent. 



211. Test for grape sugar by Trommer's or Fehling's 

 tests. After death the glycogen is transformed into grape 

 sugar, unless precautions be taken to prevent this transform- 

 ation. 



212. Saline extract of muscle (10% NaCl). The reac- 

 tion of perfectly fresh muscle to litmus is of an alkaline char- 

 acter. That of butchers' meat is acid due to the formation of 

 sarcolactic acid. A muscle tetanized for a long time becomes 

 acid. 



213. Pour a few drops of the saline extract into a large 

 quantity of water. Observe the milky deposit of myosinogen. 

 The precipitate is redissolved by adding a strong solution of 

 common salt. 



214. Test the coagulating point of another portion of the 

 extract. Four proteids are coagulated by heat, each respec- 

 tively at 47°, 56°, 63°, and 73°C., an albumose being left in solu- 

 tion. The fluid is acid in reaction. Filter off the coagula as 

 they are formed. 



215. Saturate the final filtrate with sodium chloride. 

 The myosinogen is precipitated. 



216. Collect some of the precipitate of 215 and dissolve 

 it in a weak solution of sodium chloride and test for proteid 

 reactions, — xanthoproteic and Millon's tests. 



217. Make a solution of Liebig's extract of meat. Test 

 a small portion of it for proteids. 



218. Test another portion for glycogen by adding iodine 

 solution ; a red-brown or port wine color indicates glycogen. 

 Make another test by adding a little basic lead acetate. 



219. Test another portion for kreatinin by Weyl's test. 

 Add a very dilute solution of sodium nitro-prusside, and very 

 cautiously some caustic soda ; an evanescent ruby-red color, 

 passing into a straw color, indicates kreatinin. 



