Dr. Schroeder van der Kolk on Gases, 



185 



The quantity of heat in a kilogramme of air at 4° and 0*76 

 metre pressure is less than that which it contains 



at 5° and under the pressure m, 7626 by c, 

 and 



at 5 C 



m -76 bye + 0-00005. 



Hence in the latter case more heat is contained in the air than 

 in the former. 



If a kilogramme of air at 5°, and under a pressure of 0*7626 

 metre, were allowed to expand until the pressure was - 76 metre 

 without performing any external work, as, for instance, if it were 

 placed in connexion with an exhausted space, 0-00005 thermal 

 unit would have to be added in order to keep the temperature 

 at 5°. If this quantity is not added, the temperature sinks. In 

 this way the following results are obtained : — 



Pressure. 



Hydrogen. 

 c x —c. External work. 



Difference. 



m 



0-76 



1 



2 



1-00075 



1-00093 



. 1-00183 



100047 

 1-00056 

 1-00098 



Air. 



0-00028 

 0-00037 

 000095 



0-76 



1 

 2 



0070390 

 0-070633 

 0-071873 



0-069918 

 0-070034 

 0-070633 



0-000472 

 0-000599 

 0-001240 



0-76 



1 



2 



0069470 

 0-069605 

 0070132 



0-069420 

 0-069488 

 0-069748 



0000050 

 0-000117 

 0-000384 



076 



1 

 2 



0-069435 

 0-069512 

 0-069890 



*=100°. 



0-069382 

 0-069424 

 0-069613 



0-000053 

 0-000588 

 0000277 





Carbonic Acid. 









t=3°. 





0-76 



1 



2 



0-04654 

 0-04677 

 0-04850 



0-04608 

 004620 

 0-04705 



t =100°. 



0-00046 

 0-00057 

 0-00145 



0-76 



1 



2 



0-04572 

 004602 

 0-04699 



004562 

 004577 

 004628 



o-oooio 



0-00025 

 0-00071 



