97 
of two species of the genus Ra?ia. 
It looked like water, and was almost transparent. It was 
insipid but not without smell ; it emitted an odour not unlike 
that of serum of blood. It was of sp. grav. 1003. 
It is obvious, that with its appearance its chemical nature 
must also vary. The urine, the physical properties of which 
I have described, had no effect on litmus or turmeric paper ; 
slowly evaporated, it afforded a minute quantity of brownish 
extract, which had the smell of urea. It deliquesces when 
exposed to the air ; and when decomposed by heat in a small 
glass tube, it yielded a little amber-coloured oily fluid and 
strong ammoniacal fumes; and a coal remained, in which I 
discovered a large proportion of common salt and a little 
phosphate of lime. 
Another specimen of the urine of these frogs, which I ex- 
amined, was rather more dilute. I detected in it a minute 
portion of common salt and of phosphate of lime, without any 
traces of urea. 
The urine of the brown-toad is pretty uniform in different 
instances in its appearance; and, judging from the experiments 
I have made, in its nature also. From eighty-four toads, 
caught in the streets of the Pettah,732 grains of urine were 
collected. Examined when quite fresh, it was nearly transpa- 
rent, and would have been perfectly so, but for a few minute 
flocculi suspended in it. It was of a pretty bright straw 
yellow, very like healthy human urine in appearance, with 
the peculiar smell of human urine, and nearly the same taste 
in a slight degree. It was of sp. grav. 1008. 
It did not alter litmus or turmeric paper. Nitrate of silver 
dropt into it, produced a very copious precipitate of luna 
cornea. A solution of corrosive sublimate occasioned a minute 
O 
MDCCCXXI. 
