i'}^2> en atiivral nutrition. 163 



conjecture is, That this animal derives at least a part 

 jof its food, if not the whole of it from mineral substan- 

 ces. This opinion appears bold, rather perhaps be- 

 cause we have not been accustomed to think in this 

 manner, than because it is contradicted by experience. 

 It is indeed true, that the greatest part of animals 

 which come under our more immediate observation, 

 draw their principal nutriment either from the ani- 

 mal or the vegetable kingdom ; and because this rule 

 is general we have, perhaps too hastily, concluded it is 

 universal. 



Our acute naturalist observes, " that we have no 

 clear idea of the manner in which vegetables extract 

 their nourilbment from the earth ; yet the fact being 

 so, it might not be unreasonable to suppose, that some 

 animal may derive nutriment by a procefs somewhat 

 similar." If we adopt the maxim of BufFon, ' que tout 

 ce qui pent e'tre'' est, '(whatever can be, is,) welhall be 

 led to this conclusion. " When other substances than 

 stones," Mr Burt adds, " fhall be discovered in the 

 stomach of this animal, my inference from what I 

 have seen must fall to the ground." Here, however, 

 we think the concefsion is too liberal. It may hap- 

 pen that there -may be animals, which though they 

 can derive nutriment from mineral substances, may 

 likewise be capable of extracting nutriment from 

 animal or vegetable food. All carnivorous animals, 

 ytz know, may be brought to live on grain. As just- 

 • ly might we then conclude, that if any kind of grain 

 fhould be found in the stomach ©f a carnivorous bird, 

 intermingled with animal substances, that this bird 

 derived its whok sustenance from the grain, as that 



