1865.] Liquefied Hydrochloric Acid Gas. 207 



The liquid acid is a very feeble conductor of electricity. Two fine 

 platinum wires, immersed in it f ths of an inch in length and y^-th of an inch 

 asunder, and connected with a series of 10 Smee's elements, evolved no 

 perceptible bubbles of gas, and produced only a moderate deflection 

 (amounting to 23 degrees) of the needles of a sensitive galvanometer ; and 

 this amount of conduction might possibly have been due to a minute trace 

 of oil of vitriol mixed with the liquid acid. In a second similar experi- 

 ment, with the wires y^th of an inch apart, not the slightest conduction 

 occurred on using the same battery-power, but by employing the secondary 

 current of a strong induction-coil with condenser attached, conduction and 

 a steady deflection of the needles of the galvanometer (26 degrees) took 

 place, gas being freely evolved from the negative wire only. On separating 

 the brass points of the secondary terminals beyond the distance of the 

 thickness of a thin address card, sparks ceased to pass between those 

 points, and gas was evolved copiously in the liquid acid, apparently in the 

 mass of the acid between the two platinum wires as well as at the wires 

 themselves ; two similar platinum wires in dilute hydrochloric acid in the 

 same circuit evolved very little gas. It is probable that much of the gas 

 evolved in the liquefied acid was not a product of electrolysis, but simply 

 the acid itself volatilized by the thermic or other action of the current. 

 No sparks occurred at any time in the liquid acid. It is evident there- 

 fore that liquefied hydrochloric acid gas is a very bad conductor of elec- 

 tricity, but it is not nearly so powerful an insulator as liquefied carbonic 

 acid gas. 



The following experiments illustrate its chemical, solvent, or other 

 action upon various substances immersed in it. The quantity of the solid 

 substances employed was in nearly all cases very small in proportion to 

 that of the liquid acid in contact with them, and in many cases did not 

 amount to one-twentieth of its volume. 



A piece of charcoal remained unchanged at the end of ten days, the 

 acid being in a liquid state in contact with it at intervals. A fragment of 

 fused boracic acid did not lessen in bulk or alter in appearance in seven 

 clays. White phosphorus was undissolved and unchanged in nine days, 

 and remained equally inflammable. A fragment of ordinary sulphur 

 did not dissolve or alter in several days. Fragments of vitreous black 

 selenium did not dissolve or change in six days. Iodine dissolved rather 

 freely, and quickly formed a purple-red solution. A piece of pentachlo- 

 ride of phosphorus softened in the gaseous acid, and dissolved quickly and 

 completely in the liquid acid, forming a colourless solution. A fragment 

 of sesquicarbonate of ammonia swelled and became full of fissures in the 

 gaseous acid, but neither evolved gas nor dissolved when the liquid acid 

 came into contact with it ; after three days' intermittent immersion in the 

 liquid acid, the saline residue evolved no gas on immersion in dilute hydro- 

 chloric acid. A piece of sal-ammoniac, immersed almost constantly du- 

 ring nine days, remained undissolved and unchanged. 



