t of the next mass. Meanwhile
Mr. Manross, an American gentleman, who has written a very clever and
interesting account of the lake, seems to have been so far deceived by
the curved and squeezed edges of these masses that he attributes to
each of them a revolving motion, and supposes that the material is
continually passing from the centre to the edges, when it "rolls
under," and rises again in the middle. Certainly the strange stuff
looks, at the first glance, as if it were behaving in this way; and
certainly, also, his theory would explain the appearance of sticks and
logs in the pitch. But Messrs. Wall and Sawkins say that they have
observed no such motion: nor did we; and I agree with them, that it is
not very obvious to what force, or what influence, it could be
attributable. We must, therefore, seek some other way of accounting
for the sticks--which utterly puzzled us, and which Mr. Manross well
describes as "numerous pieces of wood, which, being involved in the
pitch, are constantly coming to the surface. They are often several
feet in length, and five or six inches in diameter. On reaching the
surface they generally assume an upright position, one end being
detained in the pitch, while the other is elevated by the lifting of
the middle. They may be seen at frequent intervals over the lake,
standing up to the height of two or even three feet. They look like
stumps of trees protruding through the pitch; but their parvenu
character is curiously betrayed by a ragged cap of pitch which
invariably covers the top, and hangs down like hounds' ears on either
side."

Whence do they come? Have they been blown on to the lake, or left
behind by man? or are they fossil trees, integral parts of the
vegetable stratum below which is continually rolling upward? or are
they of both kinds? I do not know. Only this is certain, as Messrs.
Wall and Sawkins have pointed out, that not only "the purer varieties
of asphalt, such as approach or are identical with asphalt glance,
have been observed" (though not, I think, in the lake itself) "in
isolated masses, where there was little doubt of their proceeding from
ligneous substances of larger dimensions, such as roots and pieces of
trunks and branches," but, moreover, that "it is also necessary to
admit a species of conversion by contact, since pieces of wood
included accidentally in the asphalt, for example, by dropping from
overhanging vegetation, are often found partially transformed i