time during the winter,) that the waters of the lake of Morat had
suddenly become the colour of blood, though I could meet with no one
whose testimony was sufficiently clear and unequivocal to establish the
fact. This, joined to my not having the leisure then to go and see for
myself, caused the matter to slip from my memory entirely, till I found
myself in the neighbourhood. Here the circumstance was fully confirmed
to me in a manner not to be questioned; and having since met with a
paper, written by M. de Candolle, of Geneva, on the subject, I shall
take what is there stated as my best guide in mentioning the facts as
they occurred:--

"It appears that this singular phenomenon began to excite the attention
of the inhabitants of Morat as early as November last year, and that it
continued more or less observable during the whole of the winter.

"Mr Trechsel, a gentleman resident at Morat, to whom M. de Candolle
applied, on hearing the report, for information and specimens of the
colouring matter, stated--That during the early hours of the day no
extraordinary appearance was observable in the lake; but that a little
later, long parallel lines of reddish matter were seen to extend along
the surface of the water, at some short distance from the banks. This,
being blown by the wind towards the more sheltered parts of the shore,
collected itself about the reeds and rushes, covering the surface of the
lake with a light foam; forming as it were different strata of various
colours, from greenish black, grey, yellow, and brown, to the most
delicious red. He adds, that this matter exhaled a pestiferous odour
during the day, but disappeared at the approach of night. It was further
observed, that during tempestuous weather it vanished altogether. Many
small fishes were seen to become intoxicated while swimming amongst it,
and after a few convulsive leaps, to lie motionless on the surface.

"The naturalists of Geneva decided, from the specimens sent, that it
was an animal substance, which, if not the _Oscillatoria subfusca_,[72]
was nearly allied to it.

"Soon after the beginning of May it disappeared entirely. It is not
known that this phenomenon has appeared before in the lake of Morat
within the memory of man. Tradition states the same to have happened the
year preceding the great battle."[73]

A few years ago, in one of my tanks of sea-water, there occurred a
phenomenon much like this. Patches of a rich crimson-purple colour