92 
SIR B. C. BEODIE ON THE ACTION OE ELECTBICITY ON GASES. 
The probable error in these experiments is -055, and we have for the limits of pro- 
bable error 
2-72 + 0-05=2-77, 
2-72 — 0-05 = 2*67, 
the theoretical number 3 being external to these limits. 
In the second Table the value C, given in the third column, is the contraction which 
the gas after its passage through hyposulphite of soda underwent on detonation ivith 
oxygen, which is taken as representing the total oxygen formed in the induction-tube*', 
the value r= C rjT 1 
in the last column being calculated on that assumption. 
II. 
Experiment. 
I. 
T. 
II. 
Vj. 
III. 
C. 
IY. 
C— V r 
V. 
r- C-V u 
7 T 
J. 
3-61 
7-91 
13-50 
5-59 
3-41 
2. 
3-38 
9-74 
20-32 
10-58 
3-10 
3. 
3-43 
8-87 
18-59 
9-72 
2-83 
4. 
1-94 
9-53 
15-07 
5-54 
2-85 
5. 
4-34 
9-9 1 
22-23 
12-32 
2-84 
Mean = 3-01 
Noav, proceeding to calculate the value of the probable error in these experiments, we 
have as the data for this calculation 
Differences from 
the mean. 
Squares of 
differences. 
+ •4 
•16 
+ •09 
•0081 
—•18 
•0324 
-•16 
•0256 
-•17 
•0309 
Sum=-2570 
whence the probable error =0-6745 y/ 
= 0-076; 
and we have for the limits of probable error 
3-01+0-08=3-09, 
3-01-0-08=2-93. 
* [Since the above was written I have ascertained that the unabsorbed gas contains a very small proportion 
of hydrogen. This proportion, under the circumstances under which these experiments were made, is excessively 
minute, and would not affect the contraction to an extent to interfere with the conclusions as here given. The 
subject will he fully discussed in my next memoir. — B. C. B., March 16, 1874.] 
