SANTONIN. 491 



6. Myosin. Forms the principal mass of the mus- 

 cle-clot, coagulated after death during the stiffening of 

 the body. Can be obtained most readily by washing 

 out cut-up muscular substance with water, treating 

 the pressed residue with a mixture of one volume of a 

 saturated solution of sodium chloride and two volumes 

 of water, and precipitating the slimy liquid thus ob- 

 tained with water, or by the addition of sodium chlo- 

 ride. A mass, insoluble in water, also insoluble in a 

 concentrated solution of sodium chloride, but soluble in 

 a solution which does not contain more than 10 per cent, 

 of sodium chloride. It dissolves easily in very dilute 

 hydrochloric acid (4 cc. fuming acid to 1 litre of water), 

 and can be precipitated unchanged from this solution 

 immediately afterward by means of sodium carbonate, 

 but undergoes changes when left in contact with 

 hydrochloric acid. It dissolves in dilute alkalies, 

 forming alkaline compounds, the solutions of which 

 coagulate at a higher or lower temperature according 

 as they are more or less alkaline. In the yolk of egg, 

 in the crystalline lens, and a few cystic liquids, there 

 occur protein compounds, which are very similar to 

 myosin. 



7. Syntonin (Parapeptone). Is formed from myosin 

 by dissolving it in very dilute hydrochloric acid, and 

 from all other protein compounds by dissolving them 

 in concentrated hydrochloric acid. Water precipitates 

 a compound of syntonin with hydrochloric acid from 

 these solutions. It also occurs in the gastric juice, 

 being probably the first product of transformation of 

 the protein compounds. Is obtained most readily by 

 dissolving coagulated white of egg or pure fibrin in 

 fuming* hydrochloric acid, precipitating the filtered 

 solution by the addition of water, redissolving the 

 precipitate in pure water, and carefully precipitating 

 with sodium carbonate. Or chopped meat is washed 

 with water until it is colorless ; and then treated with 

 very dilute hydrochloric acid (0.1 per cent.), which 

 converts the myosin into syntonin, and dissolves it. It 

 is precipitated from the filtered liquid by neutral iza- 



