SMELL, 247 
has been commonly asserted of vultures, and also 
of the goose. In a case of this sort, observation is 
always better than the most ingenious and plausible 
theoretical reasoning ; and fortunately we possess, 
with respect to the vulture and some other birds, 
the remarks of Dr. James Johnson, which we have 
already partially referred to. “It has always,” 
says the doctor, ‘appeared to us most extraordi- 
nary, indeed unaccountable, that birds of prey could 
scent carcasses at such a distance as they are said 
to do. We were led to skepticism on this subject 
some twenty years ago, while observing the con- 
course of birds of prey from every point of the hor- 
izon to a corpse floating down the river Ganges, 
and that during the northeast monsoon, when the 
wind blew steadily from one point of the compass 
for months in succession. It was extremely diffi- 
cult to imagine that the effluvia from a putrefying 
body in the water could emanate in direct opposi- 
tion to the current of air, and impinge on the olfac- 
tories of birds many miles distant. Such, however, 
were the dicta of natural history, and we could only 
submit to the general opinion. We have no doubt, 
now that we know the general opinion to be some- 
thing wrong, that it was by means of the optic 
rather than the olfactory nerve, that these birds 
found out their quarry. 
“It has been ascertained by direct experiments, 
that where any putrid carrion was enclosed in a 
basket, from which effluvia could freely emanate, 
but which concealed the offal from sight, it attract- 
ed no attention from vultures and other birds of 
prey till it was exposed to their view, when they 
immediately recognised their object, and others 
came rapidly from different quarters of the horizon, 
where tley were invisible a few minutes before. 
This sudden appearance of birds of prey, from im- 
mense distances and in every direction, however the 
wind may blow, can only be accounted for by their 
