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PEACTICAL PHYSIOLOGY 



which are then washed out of the muscle by the blood, and appear in 

 the urine. It is on this account that the phosphates in the urine are 

 increased after muscular work. 



EXPERIMENT VI. The watery extract of muscle has been freed of 

 proteins by boiling it. Add to the clear filtrate an ammoniacal solution 

 of magnesium citrate. A white precipitate of phosphates results. 



FIG. 233. Crystals obtained from meat extract, mostly creatin, a few sodium chloride. 



Show that this precipitate consists of phosphates by dissolving it in 

 nitric acid and testing with ammonium molybdate. 



EXPERIMENT VII. As a general revision experiment test the 

 solution of commercial extract of meat provided for proteins, glycogen, 

 creatin, creatinin, mineral salts, etc. 



Preparation Of Extractives Of Muscle. 500 grammes of meat, from which 

 as much fat and tendon as possible have been removed, are finely minced ; the 

 mince is thoroughly mixed with 500 c.c. of water and heated for half an hour on 

 a water-bath at C. The extract is strained through muslin and the residue 

 extracted several times in a similar manner, tha extracts being mixed together. 



