do not rise to the surface cannot be accounted for by
ascribing marvelous properties to its waters.

The distribution of temperature with depth affords a natural
and satisfactory explanation of the phenomenon, and renders
entirely superfluous any assumption of extraordinary lightness
in the water. The true reason why the bodies of the drowned
do not rise to the surface is evidently owing to the fact that
when they sink into water which is only 4 deg. Cent. (7.2
deg. Fah.) above the freezing temperature, the gases usually
generated by decomposition are not produced in the intestines;
in other words, at this low temperature the
bodies do not become inflated, and therefore do not rise to
the surface. The same phenomenon would doubtless occur in
any other body of fresh water under similar physical
conditions.[2]

[Footnote 2: It should be noted that since 1874 there have been
remarkably few deaths from drowning in Lake Tahoe, and that the major
cases of those referred to by Dr. LeConte were of workmen and others
who were generally under the influence of intoxicants.]

(5.) _Transparency of the Water_. All visitors to this
beautiful Lake are struck with the extraordinary transparency
of the water. At a depth of 15 to 20 meters (49.21 to 65.62
feet), every object on the bottom--on a calm sunny day--is
seen with the greatest distinctness. On the 6th of September,
1873, the writer executed a series of experiments with the
view of testing the transparency of the water. A number of
other experiments were made August 28 and 29, under
less favorable conditions. By securing a white object of
considerable size--a horizontally adjusted dinner-plate
about 9.5 inches in diameter--to the sounding-line, it
was ascertained that (at noon) it was plainly visible at a
vertical depth of 33 meters, or 108.27 English feet. It must
be recollected that the light reaching the eye from such
submerged objects must have traversed a thickness of water
equal to at least twice the measured depth; in the above
case, it must have been at least 66 meters, or 216.54 feet.
Furthermore, when it is considered that the amount of
light regularly reflected from such a surface as that of a
dinner-plate, under large angles of incidence in relation
to the surface, is known to be a very small fraction of
the incident bea