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 



