242 PHYSIOLOGICAL CHEMISTRY. 



chloride. This can best be done by opening the abdomen and in- 

 serting a cannula into the aorta. Now remove the skin from the 

 lower limbs, cut away the muscles and divide them into very small 

 pieces by means of a meat chopper. Transfer the pieces of muscle 

 to a mortar and grind them with clean sand and a little 5 per cent 

 magnesium sulphate. Filter off the salted muscle plasma and make 

 the following tests : 



(a) Reaction. Test the reaction to litmus. What is the reac- 

 tion of this fresh muscle plasma? 



(b) Fractional Coagulation. Place a little muscle plasma in a 

 test-tube and arrange the apparatus for fractional coagulation as 

 explained on page 100. Raise the temperature very carefully from 

 30 C. and note any changes which may occur and the exact tem- 

 perature at which such changes take place. When the first protein 

 (para-myosinogen) coagulates filter it off and then heat the clear 

 filtrate as before, being careful to note the exact temperature at 

 which the next coagulation (myosinogen) occurs. There will 

 probably be a preliminary opalescence in each case before the real 

 coagulation occurs. Therefore do not mistake the real coagulation- 

 point and filter at the wrong time. What are the coagulation tem- 

 peratures of these two proteins? Which protein was present in 

 greater amount? 



(c) Formation of the Myosin Clot. Dilute a portion of the 

 plasma with 3 or 4 times its volume of water and place it on a 

 water-bath or in an incubator at 35 C. for several hours. A 

 typical my v sin clot should form. Note the muscle serum surround- 

 ing the clot. Now test the reaction. Has the reaction changed, 

 and if so to what is the change due? Make a test for lactic acid. 

 What do you conclude? 



2. Preparation of Muscle Plasma (v. Fiirth). Remove the 

 blood-free muscles of a rabbit as explained on page 241. Finely 

 divide by means of a meat chopper and grind in a mortar with a 

 little clean sand and some 0.9 per cent sodium chloride. Wrap 

 portions of the muscle in muslin and press thoroughly by means 

 of a tincture press or lemon squeezer. Filter and make the tests 

 according to the directions given in the last experiment. 



3. " Fuchsin-Frog " Experiment. Inject a saturated aqueous 

 solution of Fuchsin " S " into the lymph spaces of a frog three or 

 four times daily for two or three days, in this way thoroughly satu- 

 rating the tissues with the dye. Pith the animal (insert a heavy 

 wire or blunt needle through the occipito atlantoid membrane), re- 



