Dr. Schroeder van der Kolk on Gases. 183 





0*76 metre. 



1 metre. 



2 metres. 



-87 



0070390 



0070633 



0071873 



4 



0-069470 



0-069605 



0-070132 



100 



0069435 



0069512 



0069890 



Hence the value of c l — c decreases with increasing tempera- 

 ture and diminishing pressure. Taking for the limiting value 

 of k, according to the Table in § III., k — 1'00067, which in any 

 case is not far from the truth, though it cannot be quite defi- 

 nitely calculated, we have 



k 1-00067 x 29-244 3 n nrQ „ 0tt 

 C >- C= J = 422O0 =0069328, 



which gives the limit to w T hich c x — c approximates. 



If this limiting value be calculated for hydrogen, it must, if 

 reduced to the same volume, give the same number — as follows, 



k 

 indeed, from the well-known formula c l — c= y, which is appli- 

 cable to an ideal gas, and hence also to this limiting condition. 

 ForCj — cis proportional tok; and the same applies to the volumes, 

 since for the same weight, temperature, and pressure these vary 

 with k. A direct testing was not possible, since the volumes 

 determined by Regifault had to be reduced to the same limiting 

 condition ; and for this condition k, as was observed, could only 

 be determined approximately. 



Carbonic Acid. 



In the case of carbonic acid this value could be calculated for 

 3° and 100°. We have, for instance, at 3° and 0'76 metre 

 pressure, 



K = 19-0949, £=0-76, 



dyjr 

 aW 

 df 



+-■ 1 -°° 20497 ' ^=0000059951, 

 t =276-15, dr 



,_ =-0-008514. 

 dh 



The following Table was thus obtained for c^ — c'va. the case of 

 carbonic acid : — 





0*76 metre. 



1 metre. 



2 metres. 



3 



0-04654 



0-04677 



004850 



100 



0-04572 



0-04602 



0-04699 



In this case c x — c may be readily calculated for the limiting 

 condition from Gay-Lussac's law of volumes. The value of k 

 for hydrogen in the limiting condition is very nearly = 422*23. 



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