60 - M. Cagiiiard dc In Tour on the 



sufficient space to take its full degree of expansion previously lo 

 its transformation into vapour, did not always lireak imme- 

 diately after the liquid appeared to have filled the cavity in the 

 tube ; but that the explosion took place proportionably later as 

 the liquid would have been incapable of a much greater ex- 

 pansion. 



May we not draw from these facts a conclusion, that liquids 

 which are capable of but a small degree of compression at a 

 low temperature, become more compressible at a higher tem- 

 perature, and much more so in the present case, when the 

 liquid is on the point of being converted into an elastic fluid 

 under a pressure amounting probably to several himdred at- 

 mospheres ? 



It is presumed that the foregoing observations may be inter- 

 esting to those who are engaged in the application of steam 

 to engines, and they may perhaps throw some light on the 

 question proposed a short time since by the Institute on the 

 compressibility of fluids. 



By some later experiments, an attempt was made to deter- 

 mine the pressure as well as the temperature under which the 

 former results were obtained. 



The apparatus employed for ascertaining the pressiu'e was 

 so contrived, that a column of atmospheric air was compressed 

 by a short column of mercury interposed between the air and 

 the liquid contained in the tubes. 



It was found that jsether is capable of being converted into 

 vapour in a space less than double its original bulk, and that 

 in this state it exerts a pressure equal to 37 or 38 atmospheres; 

 a column of air 528 millemetres being reduced to I* mille- 

 metres in length, and the temperature of the aether being 

 equal to 160° Reaumur. — This experiment tried three times 

 gave the same result. 



Alcohol was reduced into vapour in a space a little less than 

 three times its original bulk, in which case it exerts a force 

 equal to 119 atmospheres; a column of air of 476 millemetres 

 in length being reduced to 4 millemetres, and the temperature 

 being 207° Reaumur. 



In order to ascertain the temperature, the experiments were 

 made in an oil bath, in which a mercurial thermometer was 

 inserted, while the column of air was kept at 18° Reaum. by a 

 refrigerator. 



On adding a small quantity of carbonate of soda to the water 

 submitted to the foregoing experiments, the glass was much 

 less deprived of its transparency, and it became possible to 



ascertain 



