332 On the Earthquake felt in Sicily 
differ from that of snakes in its essential nature; in every in- 
stance I have found it nearly pure uric acid. The uric acid of 
the alligator contains a large proportion of carbonate and phos- 
phate of lime. Two specimens of this urine from different alli- 
gators agreed in this circumstance ; they differed, however, in one 
having no odour, and the other a strong one of musk; the for- 
mer was from a very young, the other was from an older animal. 
3. Of the urinary Organs and Urine of the Turtle and Tortoise. 
The kidneys of the testudo mydas and geometrica, the only 
species I have hitherto examined, resemble those of the preced- 
ing animals in their lobulated structure. The proportional size 
of the kidney of snakes is greatest; that of lizards next; and that 
of the animals we are now considering, least. 
In the bladder both of the turtle and tortoise I have found 
flakes of pure uric acid, but in no great abundance: it was ina 
transparent watery fluid, containing a little mucus and common 
salt, but no urea or any other substance that I could detect in 
the small quantity on which I operated. 
It is curious to observe the links by which animals, in appear- 
ance totally dissimilar, are connected together. That there should 
be so close an analogy between the urinary organs and secretion 
of the serpent, lizard, and testudo, is not surprising, their or- 
ganic structure and their habits and ceconomy being so similar ; 
but that an analogy should exist between animals so very different 
in general appearance as birds and amphibia, is not a little sin- 
gular, yet it is true: the urinary organs of one class, as well as 
the lungs, primze vie and genital organs, resemble those of the 
other, and both are peculiar in secreting uric acid; those living 
entirely on animal food secreting it pure. 
LVII. On the Earthquake felt in Sicily in February 1818. 
Extracted from a historical and physical Memoir by Dr. 
Acatino Lonoo, Professor of Experimental Philosophy in the 
University of Catania. 
Tas memoir is divided into two parts: in the first, which: is 
purely historical, we find the detail of the facts which preceded 
or immediately followed the earthquake of the 20th of February. 
In the second, the author attempts to explain the various phe- 
nomena observed, and proposes some reflections which this me- 
morable event suggested to him. 
He begins with some account of the earthquake which took 
place in Sicily the 11th of January 1693, one of the most terrible . 
ever experienced in that country; the city of Catania was totally 
destroyed by it, 18,000 inhabitants perished under the ruins, oe 
severa 
