of the tial'iiwn. in, Fresh Water 



Fibre. 



11-02 



Gelatin. 



1-50 



In examining the muscle of salmon a mixed specimen of the thick and 

 thin was taken. It was minced, pounded, and rubbed up with an 

 equal weight of common salt ; water was then added to the amount that 

 would give a 10 per cent, solution of salt. The extract was passed 

 through muslin, the residue again rubbed up with salt, water added, and 

 the mixture filtered through muslin. The muscle was extracted in this 

 way till all the soluble proteid had been removed. It was found that, 

 as a general rule, three extractions were sufficient to remove all the 

 soluble proteid. The extract was then filtered under pressure. 

 The proteids were then estimated by heat coagulation and the gravi- 

 metric method. The following Tables show the results : 



ESTUARY. 



River. 



Tweed 

 Tweed 

 Tweed 

 Montrose 

 Helmsdale 

 Helmsdale 

 *Dee 



Tweed 

 Tweed 

 Tweed 

 Tweed 



Helmsdale 

 Spey 



*This fish was in a specially fine state of nutrition. 



UPPER WATER. 



34 



42 

 44 



21 

 69 



78 



The Tables show a considerable excess of soluble proteid in the fish taken 

 at the mouth of the river as compared with the fish in the upper reaches 

 of the stream. The fish passing up from the sea are in good condition, 



