C 285 ] 



Monf. deBufFon does not, in this account of his 

 experiment, flate the time during which the birds 

 were confined ; but as the trial mull have been made 

 in France, the fwallows which he procured could 

 not be expected to be torpid either in an ice-houfe* 

 or any other place, becaufe the feafon for their being 

 in that ftate was not yet arrived. 



I cannot alfo agree with M. de BufTon that thofe 

 birds which were mut up the longeft time died 

 through cold, as he fuppofes, but for want of food, 

 as he neither fupplied them with any flies, nor, if he 

 had, could the fwallows have caught them in the 

 dark : a very fhort fail kills thefe tender animals, 

 which are feeding every inftant when on the 

 wing . 



It therefore feems not to follow from this, or any 

 other experiment, that fwallows mud neceiTarily 

 migrate (as Monf. de BufFon fuppofes) to the coaft of 

 Senegal. 



* The very name of an ice-houfe almoft Arikes one with a 

 chill ; I placed, however, a thermometer in one near Hyde Park 

 Corner, on the 23d of November, where it continued 48 hours, 

 and the mercury then flood at 43I by Fahrenheit's fcale. 



This is therefore a degree of cold which fwallows fometimes 

 experience whilft they continue in fome parts of Europe, without 

 any apparent inconvenience ; and it fhould feem that the cold 

 vapours which may arife from the included ice, fink the ther- 

 mometer only 7 or 8 degrees, as the temperature in approved 

 cellars is commonly from 50 or 51 throughout the year.. 



Sir William Hamilton informs me, that he hath frequently 

 feen fwallows in the winter between Naples and Puzzuoli, when 

 the weather was warm ; as does Mr. Hunter, F. R. S. that he 

 hath obferved them during the fame feafon, on the confines of 

 Spain and Portugal. It fhould feem from this, that very mild 

 and warm weather for any continuance always wakes thefe birds 

 from their ftat« of torpidity, 



Swallows 



