144 
The German Spa Waters are prepared at 
Brighton, on.a large scale, .according. to 
esses invented, and improved -by)M. 
Berzelitis.and»Dr.:Struve :. these factitious 
waters, in ‘every respect, represent those’ 
of Carlsbadt, Ems; Marienbadt, Eger, Pyr- 
mont and Spa; as also those of Seltzer, 
Gelinanand Seidschutz, and: are recom- 
mended, in their appropriate cases, by the 
faculty of Brighton. 
“The Curved Top Surface of a Fluid within 
a Capillary Tube, which M. Laplace and 
other mathematicians, had considered .es- 
sentially operative in producing the eleva- 
tion or depression of such fluid, aboye that 
in which the small open tube may be in- 
serted, has lately been shewn experimen- 
tally, by M. Gillerson (in the Bib. Univ. 
vy. 27), to be an accessory circumstance ; 
such curyed surface having no direct influ- 
ence on the elevation or depression of the 
fluid. By attending carefully to the top of 
the mercury in a barometer-tube, at those 
periods when the mercury, having obtained 
the highest state, begins to lower ; or, when 
the same haying attained the lowest state, 
begins to rise ; it will be evident, we think, 
that the cohesive friction, which takes 
place between the mercury and its contain- 
ing glass tube, is the cause of retaining the 
top-edges of the mercury, either higher or 
lower than the central parts of the mercu- 
rial surface, accordingly as the column 
thereof is rising or falling: there being an 
intermediate state, as to rising and falling, 
when the surface is flat and level. 
The Absorption of Moisture, by Charcoal 
of different Woods, weighed whilst very hot, 
and again ‘after seven days exposure to a 
very damp atmosphere, has been found 
by Mr. T. Griffith to be as follows, by 100 
parts of charcoal, by weight, in each case ; 
viz., from 
Walnut-tree +«e+«+ 173 | Willow-++s+reee ees 12] 
Tulip-wood--.+»+-+ 154 | Birch-----++-++++++ 120 
‘Ash ----..---+e--- 15°3 | Rose-wood -------- 12°0 
Botany-bay wood -- 15°2 | Lime-tree-«-+------ 11°8 
Lance-wood. ------ 13°7 | King-wood -------+ 115 
wee tecncecces 13°4 | Zebra-wood ------ 66 
‘The same gentleman experimented also 
on the absorptive power of 43 different 
chemical and mineral substances, the re- 
sults of which are stated in Brande’s Jour- 
nal, No. 37: six of the extreme results are 
as follows, viz. 
: : per cent. 
per cent. | Carbonate of Strontia 
Oxide of Zinc: ----- 29°0 (native 
Sulphate of Lead -- 162 | Drawing Slate ------ ‘1 
Oxide of Chroma-- 10.0 } Chromate of Mercury ‘1 
Anhydrous Concrete Sulphuric Acid has 
been. obtained by Dr. Ure, by distillation 
from the brownish-coloured oil of vitriol 
(made at Nordhausen), of a tallowy con- 
sistence, which, on touching paper, burns 
holes through it with the rapidity of red-hot 
iron; and, dropped into water, occasions a 
‘violent ebullition. 
wee Fs 
Spirit of Philosophical Discovery. 
[Sept. 1, 
The Durability of Freestone, about to be 
exposed to moisture or frost, in the outsides 
of,| walJs’ or buildings,’ ,after/ being: raised 
from any, new quarry.or untried: bed:of-rock, 
in a particular place (the same indiyidual 
bed \of stone, as indicated:by its Contained 
organic remains; and: by the super-position 
and sub-position of other-knowmbeds, sel- 
dom continuing uniform in, its:durable and 
other properties, throughout-its;whole. ex- 
tent), may, in the course ofia fet days,. be 
ascertained, Mr. Brande says; by.saturating 
a small block-of the stone. with a solution 
of sulphate of soda; and: then’ by drying it, 
to cause the salt to crystallize, im the super- 
ficial parts of the stone; in imitation of the 
disintegrating effects of crystals of water 
or ice, in the exposed superficial parts of 
stone buildings. In the Ann. des: Mines 
vol. 9, as also in Brande’s Jaurn., No: 37, 
the processes for trying blocks of ‘stone by 
this test, are minutely described...» We are 
far, however, from considering Mr. Brande’s 
asa sufficient test of durability, in any 
untried stone, to warrant its extensive use, 
externally, in buildings; it rarely happens, 
that any beds of stone are proper for, the 
builder’s outside uses, whereof the ancient 
use of such stone cannot be discovered, 
and the durability of the same seen in 
some old walls, not very far from the in- 
tended site of anew quarry; or, what is 
still more satisfactory, cliffs, or naturally ex- 
posed surfaces, of the identical bed fixed on 
for opening a quarry therein, may ‘mostly 
be found in some bank, ravine, or water- 
course, not far from the intended quarry. 
The Importance of Steam Power to the 
success of manufacturing districts will ap- 
pear from the following particulars, ‘col- 
lected by Mr. Cleland, as to the engines 
employed in and néar Glasgow, viz. 
Average 
Number Total © Horse 
of Horse- Power 
Engines. Power. _ per 
Engine. 
In Manufactories .. 176..+. 2,970 ..16°9 
Steam-Boats:... 68....1,926 .133°2 
Collieries ..... - 58.0.0 141) 23 
Clyde Iron-works  1:... —60..60°0 
Stone Quarries... 7... 839%..5°6 
Totals, &c....310 6,406. »20°7 
Green Carbonate of Copper has, proba- 
bly, only been found in thin veins,“in a 
large quarry of magnesian limestone,” at 
Newton Kyme, near Tadcaster; and at a 
small village, called Farnham, 2 -miles 
N. W. of Knaresborough. ’ pete nga 
Optical Deception.— Dr. Roget thus ex- 
plains the curious appearance of. carriage- 
wheels, rolling along the ground »Miewed 
through the intervals of yertical bars, as of 
a palisade, or venetian. blind; 
Ulich 
spokes of the wheels appear to. 
degree of curvature, which is influen 
several circumstances, presently. t¢ 
=__-.<—--~ 
