204 



M. Achille Cazin on Internal Work in Gases. 



at the end of 0*13 second the actual pressure was less than the 

 final pressure p 1 by a quantity smaller than 221 millims. (sul- 

 phuric acid). 



From curve B, at the end of 1*4 second, the difference was 

 greater than 136 millims. The curve X X satisfies these various 

 conditions. 



Series X. (December 1867). 



Dry carbonic acid. Metal reservoir B. 



^=2*42 atmospheres, p 2 = 0'60 atmosphere. Temperature 

 between 5° and 8°. 



J0=O S -11 

 1 h=-2S mm 



t = 23 



51 



8-4 



12-3 



17-4 



22 



27 



33 



120 



-43 



-10 



+ 10 



+25 



+28 



+25 



+20 



+ 15 







r 0=0-12 

 U=+5 



2-6 



5-3 



7-9 



10 3 



16-5 



20 



26 



31 



120 



-32 



-8 



+ 12 



+22 



+30 



+27 



+22 



+ 18 







re= 1-2 



\/i=-3 



42 



7 



9-9 



11-8 



14 



175 



23 



35 



120 



-25 



-5 



+ 15 



+25 



+30 



+32 



+ 28 



+ 19 







i 0= 1-9 



3-2 



6-9 



9-8 





14-2 





25-3 



32 



120 



-26 







+20 







+31 





+25 



+20 







j 0=3-8 

 \h=-5 



5 



7-5 



11 









17-8 



24 



31 



120 



-10 







+20 









+29 



+25 



+20 







J 0=3-8 



5-2 



7-8 



12 









19 



25 



34 



120 



J>=-4 



-9 



+ 1 



+ 20 









+26 



+29 



+21 







f 0=4-8 



7-2 





13 







18-2 



26 



31 



37 



120 



+3 





+20 







+28 



+33 



+28 



+23 







J 0= 5-4 



7-7 





10-7 



15 



19-6 



30 



42 



46 



120 



+5 





+20 



+30 



+33 



+25 



+ 15 



+ 12 







j 0= 7-4 





*94 



15 





20 



31 



44 



47 



120 



... 



+ 8 



+28 



... 



+31 +23 



1 



+ 13 



+ 11 







The results of this series are collected in fig. 7, where the 

 line X' X' of the real pressure is traced in order to compare it 

 with the preceding. It cuts the axis of the abscissae at the point 

 w = 6 seconds; and its maximum is approximately at the point 

 ?/ = 30 millims., #=18 seconds. The greatest depression of 

 h occurs when for the first curve h is = — 43 (sulphuric acid). 

 Let us first remark that the maximum is nearly at the same place 

 in the two series, so that the elevation of the line X X above the 

 axis of the abscissae cannot be attributed to the motion of the 

 gaseous mass, since in Series X. the excess of pressure p x —pi 

 is half that of Series IX. This confirms the opinion advanced 

 in the preceding Section; for the fall of temperature in reservoir 

 A diminishes with p v and consequently the heat given off by the 

 sides also diminishes. The heating also diminishes in reservoir 

 B, and with it the heat withdrawn by the sides : as in Series IX. 

 the quantity of gas contained in reservoir B is greater than in 

 the other series, the heat withdrawn by reservoir B may have 

 diminished as much as the heat given up by reservoir A ; whence 



