FOOD 217 



in a fresh jar of water. Test the nitrate for proteids (serum albumin) 

 as in Ex. 91. Repeat the washing till the nitrate gives no test of pro- 

 teids. An hour or two of washing will suffice. Then squeeze out the 

 water from the minced muscle, grind up the latter with clean sand, 

 and add ten times its volume of a 10 per cent solution of common 

 salt. Stir occasionally, and after an hour or more filter through mus- 

 lin. Add some of the nitrate, drop by drop, to a large vessel of pure 

 water ; there is formed a milky precipitate of myosin, the chief proteid 

 of muscle. In the living muscle the myosin exists as the soluble 

 myosinogen. Thus in muscle there are seen to be two kinds of pro- 

 teids : one, serum albumin, soluble in water, the other, myosin, in- 

 soluble in water, but soluble in weak salt solution. 



