492 
MR. E. H. GRIFFITHS OH THE VALUE OF 
15° C. in terms of water at 15° C, = 85'340 grins. ; and from the operations indi¬ 
cated in equation (17), we get water equivalent at 25° C. in terms of water at 
15° C. = 86'174 grins. Hence 
Water equivalent = 85*340 {1 + *000977 {di — 15)].''^ 
We are now in a position to find the value of M (1 + ^ ^i — ^) for any weight of 
water at any temperature, and the value of J can then be found by equation (18). 
The following Table gives the value of M (1 -f Z t'j, — 6*) for each weight of water at 
temperatures 1 5°, 20°, and 25° C. 
Table XLII.—Value of M(1 + Z — 6>) at 15°, 20°, and 25° 
Group. 
W. 
15°. 
20°. 
25°. j 
A 
139-776 
225-116 
225-347 
225-578 
B 
188-065 
273-405 
273-572 
273-739 
0 
199-674 
285-014 
285-165 
285-317 
D 
259-500 
344-840 
344-912 
344-984 
E 
• 
277-931 
363-271 
363-318 
363*366 , 
Substituting the values of T (Table XLI.) and M (1 -f Z 6*^ — ^) in equation (18), 
we get the following values of J, The first column shows the group of experiments 
from which each value is derived. 
Table XLIII.—Values of J given by each Group at difterent Temperatures. 
Group. 
15°. 
C * 
O 
25°. 
Mean. 
A 
4-1940 X 107 
4-1940 X 107 
4-1939 X 107 
4-1940 
B 
4-1930 „ 
4-194U „ 
4-1949 „ 
4-1940 
0 
4-1939 „ 
4-1938 „ 
4-1937 „ 
4-] 938 
D 
4-1940 „ 
4-1939 „ 
4-1940 „ 
4-1940 
E 
4-1938 „ 
4-1940 „ 
4-1943 „ 
4-1940 
4-1940 
We have in the above Table given the values resulting from the calculation at 
different temperatures since the limit of our experimental errors is thus clearly 
indicated; for the values of J ought (in the absence of experimental errors) to be 
identical at all temperatures. The close agreement between the values from difierent 
groups, and from the same group at difterent temperatures, is a satisfactory proof of 
* Over the range 14° to 26° C. 
