114 Investigations on the Life- History 



(b) When the extract had been allowed to stand 24 hours at the ordi- 

 nary temperature of the room while in the process of filtering. 



40 deg. C. - - Faint opalescence. 



45 deg. C. Decided opalescence. 



46 deg. C. Precipitate (filtered). 

 48 deg. C. Faint opalescence. 

 50 deg. C. ~ Faint opalescence. 

 56 deg. C. More opalescent. 



60 deg. C. Opalescence marked. 



64 deg. C. Faint precipitate separating. 



72 deg. C. Decided precipitate (filtered). 



80 deg. C. No further precipitate. 



Here again may be noted the formation of the soluble myosin fibrin, 

 not precipitable on partial saturation with ammonium sulphate, but 

 precipitable along with the myosinogen on complete saturation with 

 ammonium sulphate the heat coagulation of the soluble myosin-fibrin 

 taking place from 40 deg. C. to 46 deg. C., the myosinogen and myoglo- 

 bulia precipitating at from 56 deg. C. to 64 deg. C. These temperature 

 results slightly differ from the temperature results got by Fiirth in the 

 case of the muscle proteids of dogs and rabbits. 



From numerous observations the myosinogen of salmon muscle 

 appears to coagulate at 55 to 58 deg. C. 



Myosinogen of salmon muscle does not appear to be precipitated by 

 dialysis, thus differing from paramyosinogen. It is completely preci- 

 pitated by heat, gives a precipitate with nitric acid. It does not 

 precipitate on the addition of dilute acetic acid. It gives the xanthro- 

 proteic reaction and the biuret reaction. 



Method. (2) The muscle in some cases was extracted with strong salt 

 (10 per cent. NaCl.) solution. It was then found that if the extracted 

 fluid was rendered acid with acetic acid, as when 1 per cent, of a 33 per 

 cent, solution of acetic acid was added, the whole proteid in the extract 

 became precipitated. Some of the extract was taken and acetic acid 

 added. The precipitate was removed, dried, and estimated. Some of 

 the precipitate obtained with acetic acid was treated with a solution of 

 carbonate of soda, when part went into solution. Thus : 



Total precipitate obtained with acetic acid, 2-415 per cent. 



Soluble in sodic carbonate solution, - - 0-665 



Residue, 1-750 



B. PROTEOSES AND PEPTONE. 



Fischel and Muira (6) have described the presence of peptone in muscle, 

 and Halliburton described a muscle albumose. Halliburton, in his later 

 work, however, has altered his opinion and agrees with Whitfield (7), 

 who shows that protooses and peptone are not found in the muscles of 

 warm-blooded animals. The same can be said of salmon muscle. In 

 examining for proteoses and peptone the fresh muscle was extracted 

 with 10 per cent, salt solution, and the extract filtered under pressure. 

 The filtrate was saturated with ammonium sulphate while boil- 

 ing. On cooling the mixture was filtered. The filtrate was entirely 

 free from proteid, thus showing the absence of peptone. The residue 

 after filtration was treated with water and filtered. The filtrate gave 

 no proteid reaction, showing the absence of albumose. These observa- 

 tions were repeated on half a dozen different fish which were selected 

 under varying life conditions from the estuaries and upper waters of the 

 rivers, and at different times of the year. 



