202 MM. Loir and Drion on the Liquefaction of Gases. 



names the oil pinakoline. It is a colourless transparent liquid, 

 with a pleasant peppermint odour. Its specific gravity is 0-8, 

 and it boils at 105°. From pinakoline the crystals of pinakone 

 could not be reproduced ; and Fittig thinks that it is not identical 

 with anhydrous pinakone, but is isomeric or polymeric with it. 



By the action of chlorine on pinakoline, bichloropinakoline, 

 C 12 H 10 Cl 2 O a , is formed. It crystallizes in fine needles, has a 

 very intense odour, and attacks the eyes violently. It boils at 

 178°. It dissolves in alcohol, from which it is precipitated by 

 water. It is not attacked by concentrated caustic potash. It 

 does not combine with alkaline bisulphites. 



MM. Loir and Drion have described* a method by which 

 many of the gases may be liquefied in considerable quantities. 

 It depends on the cold produced by the evaporation of volatile 

 liquids, which was first used by M. Bussy in the liquefaction of 

 ammoniacal gas. 



In describing the liquefaction of a gas, authors have generally 

 contented themselves with saying that it could be effected by a 

 certain freezing mixture, which in many cases has a lower 

 temperature than is absolutely necessary. Hence the liquefac- 

 tion of gases is generally thought to be a more difficult opera- 

 tion than really is the case. 



By blowing a dried current of air, by means of a blowpipe 

 bellows, through several tubes into about 7 ounces of ether, a 

 temperature of —34° C. can be obtained: this temperature, which 

 is reached in about four to five minutes, and can be kept pretty 

 constant for fifteen to twenty minutes, is more than sufficient to 

 liquefy a considerable quantity of cyanogen gas. By regulating 

 the rapidity of the air-current, it was found that the tempera- 

 ture of liquefaction is —22°. By blowing slightly through an 

 ordinary pair of bellows over the surface of the liquid gas it 

 solidifies immediately. 



By a similar arrangement a large quantity of sulphur oils acid 

 may be liquefied. 



Chlorine cannot be liquefied by means of ether cooled to — 34° 

 C. ; but when liquid sulphurous acid is substituted for ether in 

 the foregoing experiment, considerable quantities of liquid 

 chlorine may be obtained. 



Ammonia may also be obtained in the liquid state by means 

 of cooled sulphurous acid ; the minimum temperature of which is 

 — 50°, while liquid ammonia boils at — 35°*7. 



When liquid ammonia is used as a cooling agent, by rapidly 



evaporating it under the air-pump in the presence of sulphuric 



acid, a temperature of —87° C. is attained; the limit of the 



lowering of the thermometer is determined by the total solidi- 



* Bulletin de la Socie'te' Chimique, p. 184. 



