BY DR. LAUDER BRUNTON. 451 



it till the blood returns colorless by the vena cava. Cut off 

 some of the muscles of the thigh quickly, and mince them up 

 small. This is best done by a sausage-making machine. Mix 

 the mass with distilled water, stir it up well, and let it stand 

 for a quarter of an hour. Filter it through linen, aiding its 

 filtration by pressure. 



'* 60. Albuminous Substances in Muscle. Alkali 

 Albuminate- The watery extract thus obtained contains 

 alkali albuminate. It is at first alkaline or neutral, but after- 

 wards becomes acid, and the alkali albuminate is then thrown 

 down as a flocculent precipitate. The source of the acid is 

 not known. If the extract has been made from muscle which 

 has already become acid, this precipitate will not fall. 



To a portion of the extract add dilute hydrochloric, acetic, 

 or lactic acid very gradually. A flocculent precipitate will 

 fall. 



Repeat the last experiment, using exactly the same quanti- 

 ties of extract and acid, but add a little sodium phosphate to 

 the extract before acidulating it. ]S T o precipitate will fall. 

 See 15. 



Albumins Besides alkali albuminate, the extract contains 

 two other albuminous substances, one of which coagulates at 

 45 C., the other at 75 C. Filter the fluid from which the 

 alkali albuminate has been precipitated either by the develop- 

 ment or the addition of acid. Put some in a test-tube and 

 warm it in a water bath to 45 C. A precipitate will form. 

 The coagulation is not affected at all by previously rendering 

 the liquid neutral or alkaline. Let the fluid stand till the 

 precipitate subsides, and then remove it by filtration, and 

 warm the filtrate to 10 C. A second coagulation will take 

 place. 



** 61. Myosin. Free the remainder of the muscles from 

 fascia, tendons, fat, nerves, and vessels, and cut them up small. 

 Put the mass of finely-divided muscle into five or six times 

 its weight of water and stir it well. Let it stand for several 

 hours and then strain it through a linen cloth, and express 

 the fluid with the aid cf a screw-press. Treat the muscles a 

 second time with water ia the same way, and strain and press 

 again. Unite all the fluids thus obtained and keep them for 

 examination. Wash the muscle, which remains on the linen, 

 with water, as before, till it becomes of a grayish color, and 

 the water is no longer colored. 



Throw it into a mortar, and rub it up with ten per cent, salt 

 solution in sufficient quantity to prevent it from being too 

 thick and to allow it to flow tolerably easily. Let it stand for 

 several hours; filter, first through linen, then through paper, 

 and add to the filtrate several pieces of rock salt. As the salt 

 dissolves, the myosin, which is insoluble in a concentrated NaC 



