88 OF THE SENSES OF 
Kirby and Spence, following up the experiments 
of Huber, say that the olfactory sensation is convey- 
ed by “ the extremity of the nose, between it and 
the upper lip, or under those parts ;” and that it is 
analogous to this sense in mammiferous animals; and 
conceive that no one can look on an insect without 
coming to this conclusion.* But as we are not 
furnished with any experiments by which we are 
to prove that insects breathe at all through their 
head, we are at a loss how to account for the con- 
viction of these authors. And being still so im- 
perfectly acquainted with this part of the insect 
economy, we must leave it to be decided by future 
investigations. If, however, the conclusions of Dr 
Rousseau be correct,—that without the sense of 
smelling, we could have no taste, then it appears 
pretty evident that there must be spiracles in the 
mouths of insects, by which smell is conveyed to the 
sensorium. 
Rousseau made some experiments on the human 
species, by which, we think, he was fully warranted 
in adopting his theory. He successively blindfolded 
some young medical students, who were sceptical 
regarding his opinion, and after effectually stopping 
their nostrils, gave them onions to eat, which they 
took for apples, and they supposed camphor to be 
bread. 
* Krirny and Srencr, Introduction to Entomology, iv. 
p. 256. 
