268 SALMONIA. 



change first to sea green in colour, then to 

 grass green, and lastly to yellowish green: I 

 do not however, give this as a proof, but 

 only as a fact favourable to my conjecture. 



Poiet. — It appears to me to confirm your 

 view of the subject, that snow and ice, which 

 are merely pure chrystalized water, are 

 always blue when seen by transmitted light. 

 I have often admired the deep azure in cre- 

 vices in masses of snow in severe winters, 

 and the same colour in the glaciers of Swit- 

 zerland, particularly at the arch where the 

 Arve issues, in the Valley of Chamouni. 

 We thank you for your illustration. 



Hal. — In return, I ask you for some fur- 

 ther remarks on this grand waterfall. You 

 said just now, you preferred the fall of the 

 Velino for picturesque effect to any other 

 waterfall you have seen ; yet it is a small 

 river compared even with the Traun, and 

 nothing compared with the Gotha, the 

 Rhine, or above all, the Glommen. 



Poiet. — Size is merely comparative : I 

 prefer the fall of the Velino, because its 

 parts are in harmony. It displays all the 



