24 I^^^TRODUCTION. 



duces a rank state of body, wliicli is apt to cliange 

 the colour of their plumage, by affecting the ves- 

 sels which secrete the fluid that gives the colour 

 to their feathers. And, if an over-dose be given 

 to birds that have not been at all previously ac- 

 customed to it, it not unfrequently occasions 

 death in the course of a few hom's. We know, 

 that, in Ihe course of last summer, a fine bull- 

 finch and canary were lost in this manner. 



It may be thought a tri\ial circumstance to no- 

 tice the perches or sticks that birds roost upon, 

 but we know it to be of some importance; for if 

 the sticks are too small in diameter, it tends to 

 produce cramp in their feet j the perch, therefore, 

 ought to be proportioned to the size of the bii'd, 

 and well rounded and smooth, that it may be 

 easily scraped and kept clean, otherwise their feet 

 would get clogged, which injures their health. 

 The perch for a thrush, blackbird, or starling, 

 ought to be rather more than half an inch in dia- 

 meter ; and, for birds of the size of a nightingale, 

 or goldfinch, about a quarter of an inch in dia- 

 meter ; and for wrens, &c. rather less. Sky-larks 

 need none, as they never perch. 



The pure attachment of birds to each other, 

 during the important business of incubation, and 



