THE 

 LONDON, EDINBURGH, and DUBLIN 



PHILOSOPHICAL MAGAZINE 



AND 



JOURNAL OF SCIENCE. 



[FIFTH SERIES.] 



JUNE 1880. 



LII. On the Behaviour of Carbonic Acid in relation to Pres- 

 sure, Volume, and Temperature. By Prof. R. Clausius*. 



IN relation to pressure, volume, and temperature, gases 

 follow, as is well known, with a certain degree of approxi- 

 mation, the laws of Mariotte and Gay-Lussac, which can in 

 common be expressed by the following equation — 



P>=RT, (1) 



wherein p represents the pressure, v the volume, and T the 

 absolute temperature, while R is a constant dependent on the 

 nature of the gas. The further the gas in question is removed 

 from its condensation-point the closer is the approximation to 

 these laws. With those gases which under ordinary circum- 

 stances are so far from their condensation-point that, until 

 recently, their condensation could not be effected, and which 

 were therefore named permanent gases, the approximation is 

 so close that for a long time it was believed that they followed 

 these laws exactly, until Regnault, in his distinguished inves- 

 tigationsf, first demonstrated some slight deviations. Some- 

 what later, Natterer J showed that on the application of very 

 powerful pressure very considerable deviations from Mariotte's 

 law are obtained ; and the deviations observed by him were 



* Translated from a separate impression, communicated by the Author, 

 from "Wiedemann's Annalen, 1880, vol. ix. pp. 337-357. 



t Regnault, Mem. de V Acad, des Sciences, xxi. 1847. 



X Natterer, Wiener Ber. v. (1850) p. 351, vi. (1851) p. 557, and xii. 

 (1854) p. 199. 



Phil Mag. S. 5. Vol. 9. No. 58. June 1880. 2F 



