THE ~ 
EDINBURGH JOURNAL 
OF 
NATURAL AND GEOGRAPHICAL SCIENCE. 
DECEMBER, 1829. 
ORIGINAL COMMUNICATIONS. 
ART. I. On the Natural History of the Dugong, (Halicore In- 
dicus, Dusm.)—the Mermaid of Early Writers ; and particu- 
larly on the differences which occur in its Dental Characters. 
By Henry H. Cueek, Esq.* 
A POPULAR scientific periodical addresses itself to two classes of 
readers so entirely distinct, that it becomes necessary to assume 
therein a style and language appropriate toeach. ‘Thus, whilst we 
are desirous of adapting the papers we purpose to publish j in this 
Journal, to the actual state of knowledge possessed by the most 
advanced student, it is a duty which we owe to the uninformed, to 
associate with the abstruse doctrines of science, those rudimentary 
principles, by means of which alone the former can be understood. 
And we hope that these considerations will, on all occasions, be 
taken into account in the perusal of the essays which may appear 
from our pen. 
This globe, viewed as the residence of those myriads of animals 
which wander on its surface, or which sport in the bosom of its wa- 
ters, presents itself to our observation under two important aspects, 
——as land, surrounded by an etherial atmosphere,—and as sea, a 
medium of suffocating density. Oxygen, that vital air, by means 
‘of which, through the renovation of the deteriorated venous blood, 
the life of animals is sustained, must, however, be extracted from 
both the atmosphere and the water ; and nature has accordingly 
endowed her creatures with respiratory organs peculiarly adapted 
* The substance of a paper read before the Royal Physical Society of Edin- 
burgh, Nov. 3. 1829. 
VOL. I. x 
