106 ON THE SUPPOSED CAPABILITY OF THE 
the advantages of vital energy, high temperature, and 
stimulating nutriment, failed to do so. 
I shall now proceed with the experiments. Three 
young House-Martins were taken from a nest in the 
chapelry of Blakeley, near Manchester, in September, 
1827, and were kept in a room without fire. From 
the 21st of the November following to the 27th 
inclusive there was a continuance of inclement 
weather, the maximum temperature for the period 
being 47°5, the minimum 19°, and the mean 
33°:39 ; yet not the least disposition to become 
torpid was apparent in the young Martins, though 
they did not long survive the test to which they 
had been subjected : indeed, for Periodical Birds to 
suffer severely, and even to perish from cold and 
hunger during their sojourn in this country, is no 
uncommon case; but a lowering temperature and a 
decreasing supply of food, when they pass certain 
limits, are the very conditions which should induce 
torpidity in them were they liable to be so affected, 
and which actually do produce such a result in 
animals known to be endowed with this constitutional 
peculiarity. 
I myself have repeatedly seen large numbers of 
Swallows reduced to the necessity of alighting in 
fields for the purpose of obtaining some of the insects 
which a low temperature had constrained to seek 
refuge among the herbage ; and so greatly were they 
