156 
THE CABINET OF NATURAL HISTORY, 
ed the blaze. I repeatedly kindled and exploded the gas 
in this manner, but never succeeded in obtaining a steady 
blaze for any length of time, on account of the smallness 
of the quantity which issued in a stream, from the water. 
I caught a quantity of it in a number of vessels, and 
from various experiments, I have little doubt that it is 
as pure hydrogen gas as is obtained in the common pro- 
cesses of the laboratory. It is lighter than any of the well- 
ascertained hydro-carburets, and it burns with nearly the 
same pale lambent flame as common hydrogen. There is, 
however, a distinct sulphurous odour which always ac- 
companies it. My situation, however, was not favoura- 
ble for making any accurate experiments. 
The hills which surround the burning spring are strata- 
fied with beds of bituminous coal, which repose on thick 
horizontal strata of clay slate. The salt spring appears to 
be far below the clay slate. In boring the well, they were 
obliged to cut through thick strata of compact carbonate 
of lime, which alternated with strata of clay slate. No 
fossils have been found in the neighbourhood. 
In 1831, four years after my first visit to the burning 
well, when the above observations were made, I again ex- 
amined the spot; but the inflammable gas could no longer 
be detected, and the water had not the slightest saline 
taste. 
In 1S32, I again examined this Burning SaU-wdl, &x\& 
again found the water a little brackish, and a considerable 
quantity of inflammable air escaping from its surface, so 
that I fdled a number of vessels with the gas, and amused 
myself with igniting and exploding it, several times. 
SARGASSO, OR SEA WEEDS. 
In the North Atlantic Ocean, coming from the South 
you fall in about the tropic, with the Sargasso Weeds, 
collected in narrow lines extending in the direction in 
which the trade wind blows, that is, E. N. E. and W. S. 
W., and the eye cannot see the end of them on either 
side of the vessel. These lines run constantly parallel to 
each other, and the nearer you come to the middle of the 
Sargasso sea, the thicker it is strewed with weeds, and 
the closer the lines approach to one another, being in some 
places but fifteen feet asunder. Home-bound ships have 
a better opportunity of observing these lines, as they cross 
nearly at right angles, and can trace their continuation 
more conveniently on both sides, observing one line after 
another in rapid succession. 
These weeds occupy the zone from about 20° to 35° 
north latitude, which may, however, differ according to 
the longitude in which you cross it. Towards the zone’s 
northern extremes, the weeds are less regularly formed in 
lines, which may arise from their being less methodically 
acted upon by the trade winds that seem to occasion their 
order. They have been termed gulf weeds by sailors, who 
believed them to be driven out of the gulf by the Florida 
stream; nor is this opinion entirely refuted by the expe- 
rience that they are rarely met with in the gulf. For the 
weed swimming on the surface of the Atlantic is withered, 
decayed, and incrusted with salt, which proves the time 
it has been exposed to the sun, and is of a brownish yellow 
colour, whilst you rarely meet with a green bunch; that, 
being heavier, on account of its high state of vegetation, 
swims several feet below the surface. It is true that not 
with certainty can any roots, thicker branches, or stems 
be perceived, wherewith they might have adhered to the 
rocks or the ground: nevertheless, as these weeds abound 
with animals that do not live upon the surface, but inhabit 
the bottom of the sea, such as crabs, shrimps, barnacles, 
conchilias of all descriptions, and serpents, I have no 
doubt that they originated in a shallow basin of water, 
out of which they were swept by the force of a current 
along the bottom, until the heavier vegetable fluid being 
exhausted, they rose to the surface. Moreover, they are 
never seen near the European or African coasts, but most 
plentifully found about the entrance of the gulf. 
[Phil. Mug. 
EXTRAORDINARY SAGACITY OF A DOG. 
On Saturday night, a boy 12 or 14 years of age, who 
was climbing on the face of a rock in the Grange quarry, 
Edinburgh, in search of birds’ nests, fell into the deep pool 
below. His companion ran away, calling for help, and a 
crowd soon collected. A housecarpenter who was pre- 
sent, ran off to the Grange House, for Sir Thomas Lan- 
der’s Newfoundland dog. The animal immediately sprang 
in the pool, and made for the place, where the body, 
though under water, was still visible. He dived once or 
twice, and, seizing the boy’s head, which chanced to be 
uppermost, he in vain attempted to bring the body ashore; 
for, as if aware of the necessity of using the most gentle 
treatment to so vulnerable a part, he took so gentle a hold, 
that the head slipped from him, and the body sunk deeper 
and deeper at every successive attempt. Again he dived, 
and appeared on the surface raising the head gently be- 
tween his two forepaws, but again it slipped from his 
grasp, and sunk deeper than ever. The dog now seemed 
to take council with himself; he made one or two circles 
