Mr. Macartney’s Observations , &c. 259 
assistance with that liberality, which so eminently distinguishes 
him as a real lover of science. I am indebted to him for an 
inspection of the valuable journal he kept during his voyage 
with Captain Cook ; for permission to copy the original draw- 
ings in his possession, of those luminous animals discovered 
in both the voyages of Cook ; and for some notes upon the 
luminous appearance of the sea, that were presented to him by 
Captain Horsburg, whose accuracy of observation is already 
known to this learned Society. 
In the following paper, I shall first examine the grounds 
on v/hich the property of shewing light has been ascribed to 
certain animals, that either do not possess it, or in which its 
existence is questionable. I shall next give an account of some 
luminous species, of which some have been inaccurately 
described, and others quite unknown. I shall endeavour to 
explain from my own observations, and the information com- 
municated to me by others, many of the circumstances attend- 
ing the luminous appearance of the sea. I shall then describe 
the organs employed for the production of light in certain 
species ; and, lastly, I shall review the opionions which have 
been entertained respecting the nature and origin of animal 
light, and relate the experiments I have made for the purpose 
of elucidating this part of the subject. 
The property of emitting light has been reported to belong 
to several fishes, more particularly the mackarel, the moon- 
fish (tetraodon mola,) the dorado, mullet, sprat, &c. 
Mr. Bajon observed during the migration of the dorados, 
&c, that their bodies were covered with luminous points. 
These however proved upon examination to be minute sphe- 
rical particles that adnered to the surface of these fishes ; and, 
