118 SILENCE OF SINGING BIRDS. 



I will endeavour to get a hen, and examine. 



Your supposition, that there may be some natural 

 obstruction in singing birds while they are mute, and 

 that, when this is removed, the song recommences, 

 is new and bold. I wish you could discover some 

 good grounds for this suspicion. 



I was glad you were pleased with my specimen of 

 the caprimulyus, or fern-owl : you were, I find, ac- 

 quainted with the bird before. 



When we meet, I shall be glad to have some con- 

 versation with you concerning the proposal you make 

 of my drawing up an account of the animals in this 

 neighbourhood. Your partiality towards my small 

 abilities persuades you, I fear, that I am able to do 

 more than is in my power ; for it is no small under- 

 taking for a man, unsupported and alone, to begin a 

 natural history from his own autopsia. Though 

 there is endless room for observation in the field of 

 nature, which is boundless, yet investigation (where 

 a man endeavours to be sure of his facts,) can make 

 but slow progress ; and all that one could collect in 

 many years would go into a very narrow compass. 



Some extracts from your ingenious " Investiga- 

 tions of the difference between the present tempera- 

 ture of the air in Italy," &c., have fallen in my way, 

 and gave me great satisfaction. They have removed 

 the objection that always arose in my mind whenever 

 I came to the passages which you quote. Surely the 

 judicious Virgil, when writing a didactic poem for 

 the region of Italy, could never think of describing 

 freezing rivers, unless such severity of weather pretty 

 frequently occurred ! 



P. S. Swallows appear amidst snows and frost. 



