Scientific Intelligence. 167 
are formed in thin lamine, and appear to be quite similar in their 
structure to crystals of water and chlorine, with which they have a 
close analogy. ‘They remain solid ata temp. of 4° or 5° cent. but at 
that temperature they emit a portion of their gas. When the whole 
of the gas is driven off by a gentle heat, there remains nothing but 
pure water, which constituted four fifths of their weight. It is prob- 
able that ammoniacal gas, hydro-sulphurie acid, (sulphuretted hydro- 
gen?) and all other gases soluble in water, susceptible of being liqui- 
fied, might also form crystals with water, but hitherto it is not known 
that they have been obtained. 
The properties of the Liquid sulphurous acid, have been describ- 
ed chiefly either by Mr. Faraday or M. de Bussy. Itis perfectly limpid 
and transparent, and heavier than water, (sp. gr. 1.45.) When open 
to the air it disappears immediately, producing such intense cold, that 
a few drops thrown upon water produces a crust of ice, and if a 
small quantity be poured on water in a watch glass, the latter is whol- 
ly congealed into a spongy crystalline mass, a portion of the acid 
probably remaining combined with the water, while the evaporation 
of the rest, occasions the congelation of the mixture. Mercury may 
also be frozen by it. If afew drops of the liquid acid be placed on 
a quantity equal in bulk to.a small hazle nut, and the glass put under 
receiver and the air exhausted, the mercury becomes solid. A 
considerable mass may thus be congealed and preserved in that state, 
during several minutes. a 
The author has determined, by this convenient method, the elec- 
tric conductibility of mercury. By means of the double galvanome- 
ter, he has found that when two globules of mercury are properly 
adjusted between two platina points, and having the same canines» 
bility, if one of them be frozen by means of the liquid acid, it be- 
comes immediately a much better conductor than the other. Can 
this phenomenon be connected with the sudden contraction of mer- 
-cury when it freezes ? mje 
The cold produced by the evaporation of this liquid acid, was car- 
tied by M. de Bussy as far as — 60°; buthe was not able to congeal 
either absolute alcohol or ether. A remarkable fact, with respect oe 
the refrigerative powers of this liquid, is, that one part of it becomes 
congealed by the evaporation of the other, as may be shown by the 
Crystals that are formed in a watch glass by spontaneous evaporation. 
In this case the acid unites with the moisture of the air, condensed by 
the sudden cold, 
