116 Investigations an the Life- History 



filter paper, washed with water, alcohol, and ether, dried, weighed, and 

 examined for phosphorus. A number of observations were made. 

 Whenever a sufficient amount of muscle (about 500 grammes) was used, 

 phosphorus was found to be present. From this it may be con- 

 cluded that salmon flesh does contain a soluble proteid, in the molecule 

 of which an appreciable quantity of phosphorus is present. From the 

 behaviour of the extract obtained with strong salt solutions, I would be 

 inclined to hold that the soluble proteid was present as a globulin 

 loosely combined with a small quantity of phosphoric acid either as a 

 true nuclein or a pseudo-nuclein. From the results obtained I must 

 agree with Peckelharing, in so far as salmon muscle is concerned, that 

 there is a nucleo-albumin present in the flesh. It is possible that 

 Whitfield's results were got by using small quantities of flesh. 1 myself 

 got the same results when dealing with an insufficient bulk of muscle. 

 These results are confirmed by the observations on the distribution of 

 phosphrous in the muscles (p. 1 45). 



//. Insoluble Proteids. 



Solid Residue after Extraction. The solid residue, after extracting 

 the soluble proteids, was treated in the incubator for 24 hours with a 

 one per cent, solution of caustic soda. The major part of the residue 

 went into solution, the precipitate which remained representing less 

 than a third of the original material : this consisted of collagen. The 

 solution gave a copious precipitate when rendered faintly acid and 

 treated with alcohol. It gave reactions of. a proteid solution. Some 

 of the alkaline fluid was rendered faintly acid, then a copious precipitate 

 formed. Liquor pepticus and acetic acid were added, when most of the 

 precipitate disappeared. The mixture was digested for 48 hours, when 

 an increase in the precipitate took place. This precipitate was separated 

 and examined by LJr. Paton, when a distinct, though small, amoiint of 

 phosphorus could be demonstrated. This corresponds with Karajew's (8) 

 results. He found that the muscle of animals contained a body which 

 he termed myostromin a complex phosphorus containing albuminous 

 bodv soluble neither in water nor in neutral salt solutions. 



THE CURD. 



Specimens of curded salmon were examined with a view to ascertain- 

 ing the nature of the curd. 



The flesh was plunged into boiling water for three minutes, when the 

 curd became fixed. The curd was then removed from the muscle and 

 examined. It gave all the reactions of a proteid coagulum. 



It was treated with ether and pounded in a mortar, the residue 

 collected and suspended in water. The fluid gave a marked xanthro- 

 proteic reaction. 



B. Changes in the Soluble Proteids at different seasons of the year, and 

 imder differing conditions. 



A good deal of work has been done on the amount of soluble proteid 

 in the muscle of different warm-blooded animals. Demant (10) places 

 the proportion very low : 0-455 per cent, in the pectoralis major of 

 rabbits. Danilewsky (13), in the case of man, found 3*68 per cent. 



Von Konig (11) gives the composition of the nitrogenous part of the 

 salmon muscle as follows : 



