Scientific Intelligence. 167 



are formed in thin laminae, and appear to be quite similar in theif 

 structure to crystals of water and chlorine, with which they have a 

 close analogy. They remain solid at a 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 aothing but 

 pure water, which constituted four fifths of their weight. It is prob- 

 able that ammoniacal gas, hydro-sulphuric 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 

 tliat they have been obtained. 



The properties of the Liquid sulphurous acid, have been describ- 

 ed chiefly either by Mr. Faraday or M. de Bussy. It is 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 a few drops of the liquid acid be placed on 

 a quantity equal in bulk to a small hazle nut, and the glass put under 

 a receiver and the air exhausted, the mercury becomes solid. A 

 considerable mass may thus be congealed and preserved in that state, 

 during several minutes. 



The author has determined, by this convenient method, the elec- 

 tric conductibihty 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 conducti- 

 bihty, 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 ? 



The cold produced by the evaporation of this liquid acid, was car- 

 ried by M. de Bussy as far as — 60'^ ; but he w^as not able to congeal 

 either absolute alcohol or ether. A remarkable fact, with respect to 

 tire 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 v^^atch glass by spontaneous evaporation. 

 In this case the acid unites with the moisture of the air, condensed by 

 the sudden cold. 



