422 Scientific Intelligence. » 
rated for the experiment. In both cases silver was found. Its presence 
could not be distinctly proved in the ashes of coal. 
Lead an copper could not be detected in sea-water, but the ashes of 
oi 8 species of Fucus contained 000,018, .C.8. 
Ruthenium.—The atomic volume of Ruthenium has been found 
by jaa to be identical, or nearly so, with that of Rhodium, or 651-96, 
see table, page 220. 
Il. MineraLocy AND eens 
1. Description of the Vermiculite of Milbury, mae ; by Dr. 
Jackson, with an analysis by Mr. Ricnarp Crossi v, (sbenmuenian 
by Dr. Jackson.)—This mineral was first sitet in ilbury by Dr. 
Thomas H. Webb of Providence, R. I., and was described by him in 
the American Journal of Science in 1824, yol. vii, p. 55. Dr. Webb 
gave it the name it bears, eae is very descriptive of its remarkable 
action under the influence of heat. It occurs in small scales resembling 
green talc disseminated throughout a mealy magnesian mineral of an 
ash grey color, and resembling a decomposed talcose rock. The ver- 
miculite occurs in small scales, rarely more than one- uiuth of an inch 
in diameter, and having no well defined lateral crystalline edges; but 
still they are obviously imperfect crystals and probably hexagonal 
prisms. They split peat into thin lamine, like talc, and are flexible, 
but not elastic. Hardness 1°; sp. gr. according to Mr. R. Crossley, 2°756, 
the mineral having been Sada dry previous to being weighed. Color 
dark olive green by reflected light, with a pearly and greasy lustre ; b 
transmitted light, color apple green. ‘Translucent, and sub-transparent 
in thin scales. Before the blowpipe a thin scale of the mineral sud- 
denly exfoliates and swells into a cylinder or prism nearly one hundred 
times its original length! This exfoliation takes place at a temperature 
between 500° and 600° F., and not at a temperature of 300° F., hence 
it is mat wholly due to interposition of water between the laminw of the 
crysta 
Ina ee tube closed at one end, on heating until exfoliation takes 
lace, a certain portion of water is given off, but on raising the heat to 
redness a still larger quantity is obtained. This water restores the 
blue color to litmus paper, that had been reddened by acids, and is 
therefore slightly alkaline. The expansion of vermiculite by heat Is 
so sudden and powerful as to burst a glass tube filled with it, producing 
an audible oe heen and scattering the glass to a distance 
In the platina forceps a scale of the vermiculite melts” readily into a 
yellowish green glass. With carbonate of soda it fuses to an opaque 
brown bead. With borax it dissolves rena giving a yellow glass 
while hot, which becomes colorless when cold. 
’ ith salt of phosphorus, it dissolves Tivibg a transparent glass, i 
is yellow while hot, and colorless when cold, and becomes som what 
milky white. It is decomposed by chlorbydrie and sulpburic wie. 
Mr. Crossley used a mixture of these two acids in decomposing t e 
mineral Fad separation of its pperecieniag % ering previously ascertain ned 
that its its decomposition by acids was comple : es 
