M. E. Wiedemann on the Specific Heats of Gases. 103 



The specific heat found between 200° and 25° is almost 

 identical with the number 0*22616 obtained by Regnault. 

 From Regnault's experiments carried out for the temperature- 

 interval 165° to 200°, as well as from my own results, it ap- 

 pears that the specific heat of nitrous oxide increases with 

 increase of temperature. 



From the foregoing measurements the following true specific 

 heats are deduced : — 



For 0-1083 



100 0-2212 



200 0-2442 



Multiplying these numbers by the specific gravity of nitrous 

 oxide (1°52) we obtain the relative heats : — 



For 6 0-3014 



100 0-3362 



200 0-3712 



Ammonia. 



The gas was prepared by gently warming the strongest am- 

 monia of commerce, and dried by passage through a long tube 

 filled with lime. 



In order to regulate the velocity of the flow, the gas was 

 passed through a small flask containing mercury and then 

 through an empty flask. 



The manometer (k) contained concentrated ammonia instead 

 of water during the following experiments. A three-way 

 stopcock served to lead away the excess of gas after leaving 

 the balloon. 



Table I. — Experiments between 100° and 25°. 



l. 



60-38 

 16-12 

 753-3 

 60-0 



19'8 

 4 



4-03 

 199 

 179 



0-08 

 25-8 

 -0033 



00513 



0-0143 



7-76 



7-68 

 22-9 

 998 

 77-8 



0-5226 



61-45 

 13-97 

 752*46 

 69-04 

 163 



3 



4-66 

 160 

 16-38 



0-078 

 23-45 

 -005 



0-0848 



0-0180 



6-79 



6-76 

 20-0 

 99-7 

 79-5 



0-5164 



3. 



60-33 

 1338 

 749-62 

 70-59 

 17-2 



3 



4-46 

 15-9 

 159 



0-086 

 23-03 



000 



0-086 



0-012 



6-83 



6-7 

 196 

 99-6 

 80 



05246 



59-77 

 15-12 

 747-62 

 73-04 

 17-00 



H 



454 

 16-85 

 16-4 



0-101 

 24-39 

 -0-0075 



0-095 



0-0136 



7-69 



754 

 20-55 

 99-6 

 79-05 



0-5226 



5. 



60-9 

 14-78 

 749-68 

 60-32 

 17 



3* 



4-22 

 16-75 

 15-8 



0-098 

 23-24 



0-0025 



0-087 



00130 



7-24 



7-06 

 19-6 

 99-6 

 80 



0-5108 



6. 



60-62 

 16-41 

 747-4 

 61-2 

 25 



4 



410 

 25-15 

 22-65 



0-098 

 30-50 

 -0-013 



0-063 



0-014 



7-44 



7-28 

 26-82 

 102-0 

 75-2 



0-5173 



