ON THE SINGING OF BIRDS. 
before been scientifically treated of,* it may 
not be improper to prefix an explanation of 
some uncommon terms, which I shall be obliged 
to use, as well as others which I have been 
under a necessity of coining. 
To chirp is the first. sound which a young 
bird utters, as a cry for food, and is different 
in all nestlings, if accurately attended to; so 
that the hearer may distinguish of what species 
the birds are, though the nest may hang out. Be 
his sight and reach. 
This cry is, as might be expected, very weak 
and querulous; it is dropped entirely as the 
bird grows stronger, nor is afterwards inter- 
mixed with its song, the chirp of a nightingale 
(for example) being hoarse and disagreeable. 
To this definition of the chirp, I must add, 
that it consists of a single sound, repeated at 
very short intervals, and that it is common to 
nestlings of both sexes. 
The call of a bird, is that sound which it is 
able to make, when about a month old; it is, 
in,most instances (which I happen to recollect) 
* Kircher, indeed, in his Musurgia, hath given us some few 
passages in the song of the nightingale, as well as the call of a 
quail and cuckow, which he hath engraved in musical charac- 
ters. ‘These instances, however, only prove that some birds 
have in their song, notes which correspond with the intervals of 
our common scale of the musical octave. 
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