286 M. Achille Cazin on Internal Work in Gases. 



Example I. — I consider, as in § I., a kilogramme of carbonic 

 acid gas contained in the apparatus at ordinary temperature ; a 

 pump causes the gas to pass from reservoir B into reservoir A 

 up to the pressure of 3*8 atmospheres. 



In order to know the weight m l of gas which is in reservoir A, 

 it will suffice to calculate by formula (6) the specific volume v l 

 under a pressure of 3*8 atmospheres and at Tj = 283°; we find 



^ = 0-13514 cub. m. 



I have previously supposed 



V 1 ==O-1088'XcuXj^i 



V 2 =0*41185 „ 



numbers which are in the ratio of the capacities of my appara- 

 tus; then 



V 

 ?n,= — - =0*80442 kilogramme-. 



v x ° 



The weight m 2 of gas left in B is simply 



m< 2 =l—m 1 = 0*19558 kilogramme. 

 It is also easy to calculate the pressure^ of the mass m r 

 In fact its specific volume 



v 2 = ^ =2*10582 cub. m. 



Consequently the pressure is calculated by formula (6) ; and 



jo 2 = 0*24 atmosphere, 

 a number which differs very little from that of Series IX. 



Introducing the values of V„ V 2 , m { , m 2 into formula (23), we 

 find 



0=281°-25, 



T 2 -6>= l°-75; > 



then, with formula (24), 



p' = 756*68 millims., 



p—p f = 4*62 „ 

 because 



^ = 761-30 (p. 273, §L). 



Example II.— Let us put^ = 2*425 atmospheres as in Series X. 

 Following the same process, it is found that 



v x =0*21338 cub. m., 

 m x - 0*50947, 

 m 2 = 0*49053, 

 v 2 =0*83960, 



