The only other appearance which I have
to notice, is a thin oily coat on the water which displays
iridescent colours. I saw a considerable tract of the ocean thus
covered on the coast of Brazil; the seamen attributed it to the
putrefying carcass of some whale, which probably was floating at no
great distance. I do not here mention the minute gelatinous
particles, hereafter to be referred to, which are frequently
dispersed throughout the water, for they are not sufficiently
abundant to create any change of colour.
There are two circumstances in the above accounts which appear
remarkable: first, how do the various bodies which form the bands
with defined edges keep together? In the case of the prawn-like
crabs, their movements were as coinstantaneous as in a regiment of
soldiers; but this cannot happen from anything like voluntary
action with the ovules, or the confervae, nor is it probable among
the infusoria. Secondly, what causes the length and narrowness of
the bands? The appearance so much resembles that which may be seen
in every torrent, where the stream uncoils into long streaks the
froth collected in the eddies, that I must attribute the effect to
a similar action either of the currents of the air or sea.
Pages:
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70