240 Faculty of Scent in the Vulture^ 



quite satisfied that it is directed to its food by means of its 

 olfactory nerves coming in contact with putrid effluvium, 

 which rises from corrupted substances through the heavier 

 air. Those are deceived who imagine that this effluvium 

 would always be driven to one quarter in the tropics, where 

 the trade-winds prevail. [Vol. II. p. 473.] Often, at the 

 very time that the clouds are driving from the north-east up 

 above, there is a lower current of air coming from the quarter 

 directly opposite. This takes place most frequently during 

 the night-time, in or near the woods ; and it often occurs 

 early in the morning, from sunrise till near ten o'clock, when 

 the regular trade-wind begins to blow. Sometimes it is noticed 

 in the evening, after sunset ; and, now and then, during the 

 best part of the day, in the rainy season. In Guiana there is 

 a tree called hayawa : it produces a deliciously smelling resin, 

 fit for incense. When the Indians stop on the banks of a 

 river for the night, they are much in thehabit of burning this 

 resin for its fine and wholesome scent. It is found in a hard- 

 ened lumpy state, all down the side of the tree out of which 

 it has oozed. It is also seen on the ground, at the foot of the 

 tree, incorporated with the sand. When we had taken up 

 our nightly quarters on the bank of the Essequibo, many a 

 time we perceived this delightful fragrance of the hayawa, 

 which came down the bed of the river to the place where 

 we were, in a direction quite opposite to the trade-wind. My 

 Indians knew by this that other Indians were encamped for 

 the night on the river-side above us. 



When the eruption took place in the Island of St. Vincent, 

 in the Caribbean Sea, in 1812, cinders and other minor par- 

 ticles of matter were carried nearly, if not fully, 200 miles 

 to windward, and were said to have fallen at or near Barba- 

 does. Had there been a carcass, in a state of decomposition, 

 at the place during the time of the eruption, no doubt the 

 effluvium arising from it would have been taken to windward 

 by a temporary counter-aerial current; and a vulture in 

 Barbadoes might probably have had pretty certain inform- 

 ation, through his olfactory nerves, that there was something 

 good for him in the Island of St. Vincent. 



Vultures, as far as I have been able to observe, do not 

 keep together in a large flock, when they are soaring up and 

 down apparently in quest of a tainted current. Now, suppose 

 a mule has just expired behind a high wall, under the dense 

 foliage of evergreen tropical trees ; fifty vultures, we will say, 

 roost on a tree a mile from this dead mule ; when morning 

 comes, off they go in quest of food. Ten fly by mere chance 

 to the wood where the mule lies, and manage to spy it out 



