124 Dr Turner on the Detection of 
sponge are mentioned by that author, merely as a matter of 
vulgar report (&/? without adducing the authority of any 
observer ; whereas he expressly states, that those who inhabited 
Torona did not believe in the existence of any such property in 
this animal. The naturalists to whom Aristotle refers, and with 
whose evidence he appears satisfied, from not mentioning those 
who were of an opposite opinion, had certainly the best means 
among the Greeks of observing the phenomena of this animal, in 
its living state* from their southern exposure and warm latitude, 
on the shores of Macedonia, only 17° from the Torrid Zone, and 
from their sheltered situation at the head of the present Bay of 
Cassandria, where the delicate zoophytes, which covered their 
rocky coasts, were protected from the tempests of the ACgean 
Sea, by the long and mountainous promontories of Pallene, Si- 
thonia, and Athos. 
From this extraordinary inertness of the sponge, under every 
circumstance, to the strongest artificial excitement ; and from 
the circumstance shewn above, of its not contracting its body 
spontaneously, during the flow of the currents, we feel compelled 
to ascribe that function, for which the whole body of the animal 
seems so admirably constructed, to some powers which are in- 
cessantly in action, while the general mass of the zoophyte is at 
rest. We shall now try, if possible, to discover those moving 
powers which seem to contain the secret of this mysterious be- 
ing ; but, before entering on this new kind of investigatipn, it is 
necessary to give an outline of the internal structure of the ani- 
mal, that we may enter, with more minuteness of detail and pre- 
cision of language, into what relates to the functions of its indi- 
vidual parts, 
( To be continued.) 
Art. XIX. — On the Detection of Boracic Acid in Minerals 
by the Blowpipe * By Edavard Turner, M. D. F. R. S. E. 
Lecturer on Chemistry, and Fellow of the Royal College 
of Physicians, Edinburgh. 
In the paper which I had the honour of reading before the 
Society at its last meeting, on the detection of lithia in minerals, 
* Read before the Royal Society of Edinburgh on the 19th December 1825. 
