358 Messrs. Trowbridge and Richards on the Temperature 





The Resistance of Nitrogen. 







Number of half-oscillations. 



Eesi 



stance in ohms. 



Pressure 

 of gas. 

























Capacity 



Capacity 



Capacity 



Capacity 



Capacity 



Capacity 





= 6000. 



= 12,000. 



= 18X00. 



= 6000. 



= 12.000. 



= 18,00U. 



millim. 







(ohms.) 



(ohms.) 



(ohms.) 



9-5 





1 







30 





5 



1 (faint) 



14 



H 



35 



25 



23 



42 





n 







25 





27 



2 





s" 



20 





ib 



2 



2 



£ 



2(?) 



20 



20 



15 



17 





3 







15 





1-3 





3 







15 





104 



3 '" 



4 



£ 



15 



10 



"s 



0-70 





4 







10 





0*50 



sf 



5 



i" 





8 



7 



030 



4 





6 



12 





5 



0-26 



5* 





**(') 







55 



0-22 





8* 







4-5 





015 



h" 



8£ 





"i 



4 





007 



5 



8 





10 



4-5 





0-05 





7 







5 





0-03 





8 







4 





002 





5 







8 





001 





5 







8 





0-005 



_no spark. 



no spark. 



no spark. 



very high 



very high 





Besides these measurements of hydrogen and nitrogen, 

 several photographs were made of sparks sent through 

 some of Lord Rayleigh's argon contained in sealed tubes. 

 Since the capillaries were not in every case equal in diameter, 

 the results are not wholly comparable with one another, or 

 with those in the two tables given above. Two half-oscilla- 

 tions each were observed in the photographs of argon at 1, 2, 

 and 3 mm. pressure contained in tubes with very fine 

 capillaries, while six half- oscillations were observed in tubes 

 about like those used for nitrogen and hydrogen. This shows 

 that the form of the tube influences ygtj materially the 

 resistance. As a very small jar will provide enough elec- 

 tricity to give the blue spectrum of argon, the resistance 

 of a tube containing the gas at 1 mm. pressure was deter- 

 mined with a capacity of about 1000 as well as with the 

 usual capacities 6000, 12,000, and 18,000 electrostatic units. 

 Somewhat over six half-oscillations were observed in each case, 

 corresponding to resistances of about thirteen, eight, six-and- 

 a-half, and five ohms respectively. 



