| c e . briny particles, than what adhere to its outfide. A ll this perfe&lÿ
agrées with the curious fad related by Mr. A d a n son who had
brought to France two bottles, o f . lea- water, taken up indifferent
parts o f the ocean, in order to examine it and to .compare its falt-
nefs, when more at leifurej but. both, the bottles containing- tho
falt-water were burfl by being frozen, and the water produced'from
melting the ice, proved perfectly frefh. This faû is fo fairly Rated;
and fo very natural, that I cannot conceive it is necefîâry to
fuppofe -jr, without the leaf! foundation for it,, that the battles were
changed, or that Mr. Adanfon does not mention the circumjlanee by
•which the fea-water was. thus altered upon its being dijjolved: for as
he exprefsly obferves the bottles to have been burfl, i t is obvious
that the concentrated- briny parts ran out- and were entirely drained
from the ice, which was formed o f the frefh water, only:
T h e ice formed by- Dr. Higgins from fea-water, conjified of ' thin
lamince, adhering to each other weakly.. Dr. Higgins took out the
frozen ice. from the. veffels> wherein he expofed the fea-water, and
continued to do fo till the- remaining concentrated fea-water began
to form cryflalsi of fea.fait.. Both thefe experiments therefore b y no
means prove what the Dr. intended to infer from thence ; for it
was wrong to take out fueh ice, which only confijled of thin làmintSi
adhering to each other weakly. Had he waited, with patience, he
would
-j- Adanfon Hiftoire naturelle du Senegal. Paris 1757, 4to. p. 190.
* Second fupplêment, to the Probability of reaching the North Pole,, p. 119,
would have obtained a hard ice as well as Mr. Nairne, which, by a
more perfect congelation, would have excluded the briny particles
intercepted between, the thin lamina, adhering-to each other weakly ;
and would have connected the laminae, by others formed by frefh
water. Th e Dr. found afterwards, it is true, thicker and fomewhat
more folid ice, in the veffel B : but the fea-water had already been
fo much concentrated by repeated congelations, that It -is -no wonder
the ice formed in it, became at lalt brackifh : it fhoüldTeem then,
that no conclufive arguments can be drawn from thefe. experiments..
There are two other objections againfl the formation o f the ice in
the great ocean ; Ùiefirjl is .taken from the immenfe bulk and lize o f
the ice maffes formed in the ocean, which is the deepeft mafs of water
we -know of * . But the reader is referred to the tablé communicated
above, where it appears, that in the midft-of furnmer, in the latitudes
o f 55°, 550 26', and 64° South, at too fathoms depth, the thermometer
was at 340, 3 4!“ and 32°; and that in all inflances, the difference
between the temperature at top and at 100 fathoms depth,-
never exceeded 4 degrees, o f Fahrenheit’s thermometer, o f that the
temperature of the air did not differ five degrees from that-bf the
ocean at 100 fathom-deep. I f wé now add to this, that beyond
N 2 the
"’*■ Dr- Higgins’s experiments, in thé fécond fupplementto the Probability, &c. p. 14 t.
ICE.