of t/ie Salmon in Fresh Water. 115 



C. THE PRESENCE OP ALBUMIN. 



Halliburton describes an albumin as present in muscle plasma. 1 

 have made a very large number of observations on the muscle of salmon, 

 but have been unable to satisfy myself of its constant presence. If the 

 extract of salmon muscle was treated with an equal volume of saturated 

 ammonium sulphate solution and rendered slightly acid with acetic 

 acid, as a rule the entire proteid present was thrown down. If any 

 proteid remained in solution it was a mere trace. The presence of a 

 mere trace of albumin might result from the imperfect washing away 

 of the blood from the flesh, as from the method in which the flesh 

 was obtained it was impossible to perfuse, and so remove all the blood. 



D. NUCLEO-ALBUMIN. 



The presence of nucleo-albumin in muscle is a subject which has been 

 a good deal discussed of late. Whittield (7) expressly denies its 

 presence, stating that myosin is not a nucleo-albumin, because it contains 

 no appreciable quantity of phosphorus in its molecule, because on gastric 

 digestion only an insignificant residue is obtained which contains no 

 phosphorus, and because when injected into the circulation it does not 

 produce in tra vascular coagulation. He concludes that muscle contains 

 no nucleo-albumin, because after digestion it yields only an insufficient 

 residue, and this contains no appreciable quantity of phosphorus. In 

 a still more recent paper Peckelharing (9), however, reaffirms the 

 presence of nucleo-albumin in muscle. 



I have made a large number of observations on the muscle of salmon. 

 In all of them the phosphorus estimation was carried out by Dr. Noel 

 Paton. 



In extracting the proteid different methods were used. 



(1) The flesh was extracted with 10 per cent, salt solution. The 

 extract obtained was filtered first through muslin and then through 

 filter paper under pressure. A large quantity of the extract was taken 

 and to it 1 per cent, of a 'A3 per cent, solution of acetic acid was added. An 

 enormous precipitate was obtained in every case on the addition of the 

 acetic acid.* This precipitate was collected, washed, dissolved in 1 per 

 cent, solution of sodic carbonate, reprecipitated with acetic acid, collected, 

 and redissolved in sodic carbonate solution. The purification was repeated 

 three times. The solution was then injected into the veins of a brown 

 rabbit by Dr. Paton with negative results. It should be noted, how- 

 ever, that since this observation was made Halliburton (12) has pointed 

 out that if nucleo-albumin be subjected to repeated purifications, it loses 

 its power of producing intra- vascular coagulation. 



(^) The precipitate obtained on the addition of acetic acid to the 

 extract made with strong salt solution was separated, washed with 

 acidulated water to free it of inorganic phosphates, and dried upon a 

 porous plate. A small quantity, less than half a gramme, was examined 

 for phosphorus, and a distinct but small trace was found. 



(3) Several specimens of salmon muscle were examined by Peckelhar- 

 ing's method. Five hundred grammes of the salmon muscle was 

 extracted with weak salt solution (1-5 grammes NaCl. per litre). The 

 extract was filtered and the residue again extracted. The fluid thus 

 obtained was filtered, and dilute acetic acid solution added ; a slight 

 precipitate formed. Hydrochloric acid and liquor pepticus were added 

 and the mixture put to digest for 48 hours. A considerable increase in 

 the precipitate took place. It was thrown upon a weighed ash-free 



* It should be noted that the acetic acid solution carried down the entire proteid in 

 solution in most cases. 



