xiXD ON THI'] LAW OF PliESSURE OF (4ASES, ETC. 
221 
Table YlII.—Hydrogen. October-November, 1900. 
Pressure iii 
Deviation 
Error of p 
1 
1 Pressure in 
Deviation 
Error of p 
inillims. Hg. 
of 
in millims. 
millims Hg. 
of pv. 
in millims. 
1 • 43 
+ 
•0025 
+ 
•0036 
1-44 
4- 
•0018 
+ 
•0026 
1-31 
+ 
•0030 
4- 
• 0039 
1-lS 
- 
•0005 
- 
•0006 
1-20 
"r 
•0002 
+ 
•0002 
1-00 
+ 
•0009 
+ 
•0009 
1-11 
— 
•0012 
— 
•0013 
•87 
+ 
•0007 
4" 
•0006 
•97 
— 
• 0005 
— 
•0005 
* 77 
+ 
•0005 
4_ 
•0004 
•86 
— 
•0002 
— 
• 0002 
•62 
•0000 
•0000 
* 77 
_ 
•0016 
— 
•0012 
* 57 
— 
•0028 
— 
•0016 
•70 
— 
•0025 
•0017 
•52 
_ 
•0009 
— 
• 0005 
•64 
+ 
•0007 
+ 
•0004 
•48 
— 
•0018 
— 
• 0009 
— 
— 
•42 
+ 
•0018 
+ 
•0008 
•769 
+ 
•0021 
-L. 
•0016 
• 386 
•0000 
•0000 
•624 
H- 
•0028 
+ 
•0017 
•315 
+ 
•0014 
+ 
•0014 
•524 
•0000 
• 0000 
•264 
_L 
1 
•0023 
j_ 
•0006 
•423 
1 
T 
• 0002 
+ 
•0001 
•213 
+ 
•0014 
4- 
•0003 
• 335 
— 
• 0037 
- 
•0012 
•168 
- 
•0072 
— 
•0012 
•279 
- 
•0018 
- 
•0005 
•140 
— 
•0014 
- 
•0002 
•196 
-r 
•0079 
-h 
•0015 
•098 
- 
•009 
_ 
•0009 
•158 
+ 
•0046 
+ 
•0007 
•080 
•000 
•0000 
•133 
+ 
•0053 
+ 
•0007 
•068 
+ 
• 005 
4" 
•0003 
•106 
_ 
•0053 
— 
•0006 
•055 
+ 
•007 
4- 
•0004 
•085 
_ 
•0037 
— 
•0003 
•044 
•007 
4- 
•0003 
•070 
- 
•0083 
- 
•0006 
•036 
•005 
- 
•0002 
•051 
+ 
•007 
+ 
•0004 
•027 
_ 
•047 
_ 
•0013 
•041 
+ 
•002 
+ 
•0001 
-023 
+ 
•016 
4- 
•0004 ! 
•034 
— 
•009 
•0003 
•018 
— 
•054 
— 
•0010 1 
•027 
— 
•023 
•0006 
•016 
4“ 
•021 
4- 
•0003 : 
•023 
+ 
•036 
+ 
•0009 
•013 
4- 
•040 
4- 
•0005 1 
•018 
— 
•014 
— 
• 0003 
•010 
+ 
•019 
4- 
•0002 : 
j 
In several of the sets of observations recorded in Table VIII., there would seem to 
be a tendency for the positive errors to concentrate towards the beginning, i.e., for 
pv to diminish slightly with p. It was at this stage that a suspicion arose that the 
distance between the glass points of the manometer might not be cpiite constant, but, 
as has Ijeen related, the suspicion was not verified. It is just possible that at the 
higher pressures and smaller volumes the temperature changes were not insensible. 
It is probable that they would operate in the direction mentioned, inasmuch as at 
the smaller volumes a larger proportion of the gas would be in the connecting tubes 
at a higher level in the room, and therefore warmer. Considerable precaution was 
taken, and I was not able to satisfy myself that disturbance due to temperature 
really existed. In another series of observations on hydrogen the tendency was 
scarcely apparent, and it remains doubtful whether there is any real indication of 
departure from Boyle’s law. It may be noted that interest was concentrated 
rather upon the lower pressures, and that perhaps less pains were taken over the 
