72 ‘Scientific Intelligence. [Juny, 
pound of the black substance with ammonia, and possessed the fol- 
Jowing properties: Las tna) 
It was very soluble in watcr; and, on being heated with caustic 
potash, it gave off the smell of ammonia. ‘The black compound, 
however, did not appear to have any tendency to assume the crys~ 
talline form. 
In evaporating to dryness, on a piece of glass, the ammoniacal solu- 
tion in which the black substance had been dissolved, the residuum 
split into most minute fragments, having a regular and very peculiar 
appearance, especially when examined with a magnifier. 
From the solutions of this compound in water, muriate of barytes 
and nitrate of silver produced copious brown precipitates, as did also 
protonitrate of mercury and nitrate of lead ; but oxymuriate of mercury 
produced no immediate precipitate, and that obtained from acetate 
of zinc was of a paler brown colour. 
From these experiments Dr. Prout concludes that the remarkable 
specimen of urine in question owes its black colour to a compound of 
a peculiar principle with ammonia, as Dr. Marcet had inferred from his 
own trials; but he is moreover inclined to think that the black principle 
itself, such as obtained from the urine by the action of dilute acids, 
may be considered as a new body possessed of acid properties. From 
the small quantity of the specimen, however, which could be spared 
for Dr. Prout’s experiments, it was impossible to obtain complete and 
decisive evidence on the nature of this substance; but it appears to 
be sufficiently characterized as a peculiar acid, and to bear a closer 
anzlogy to the lithic acid, or rather to some of the compounds which 
it forms when acted upon by the nitric acid, than to any other principle 
usually found in the urine. 
Should this view of the subject be confirmed by farther observations, 
Dr. Prout would propose to distinguish this new substance, on account 
of its black colour by the name of Melanic acid. 
Ill. Details ofa remarkable Phenomenon, which occurred in the Commune 
of Juvinas, June 15, 1821. 
The following extract from the Register of the Civil Department 
of Juvinas appears worthy of notice, not merely from the fact 
which is there recorded, though it is curious, but from the nature of 
the recital. It is astonishing, that in the 19th century the narration 
of a well-known meteorological phenomenon should be accompanied 
by the relation of circumstances which recall the ignorance of past 
ages; that five hundred devils should be named as the presumed 
agents of the fall of an aerolite; and that to discover this stone, 
? was judged more proper to carry holy water than mattocks and 
evers. 
That a proces-verbal, in which all these absurdities are recorded, 
should be signed by magistrates, filling important offices, is still more 
surprising. 
The frequent fall of aerolites, during the last fifty years, has fixed 
the attention of naturalists to the subject. It is generally in calm 
weather, observes M. Leman, under a cloudless sky, that these phe- 
nomena are observed: a ball of fire is: perceived, which traverses a 
certain space, variable in its direction, and which soon bursts with a 
