262 
DR. II. T. BARNES ON THE CAPACITY FOR HEAT OF WATER 
Rowland’s values are those given by W. S. Day (‘ Physical Review/ vol. 7, p. 193, 
1898), corrected to the Paris scale. Griffiths’ values are those quoted by Schuster 
and Gannon in their paper. At 20° and 25° Griffiths’ own temperature coefficient 
is used. Schuster and Gannon’s value is given in their paper at a temperature of 
19°*1 C. I have reduced it to 20° by the temperature coefficient obtained in my 
experiments, which is very similar to Griffiths’ over a short range. It will be seen 
that the values of Griffiths and Schuster and Gannon are brought into closer 
agreement when corrected to the same value of the Clark cell. 
Extrapolating for the values of J above 100° C. we obtain from the formula 
J, = J 55 (1 + -000120 (t - 55°) -b -00000025 (t - 55 0 ) 2 ) 
the following values 
Temperature 
Centigrade. 
J. 
(J 55 = 4-1819). 
J. 
(J 55 = 4-1764). 
o 
110 
4-2127 
4-2072 
120 
4-2190 
4-2135 
130 
4-2255 
4-2199 
140 
4-2321 
4-2265 
150 
4-2390 
4-2334 
160 
4-2461 
4-2405 
170 
4-2534 
4-2479 
180 
4-2610 
4-2554 
190 
4-2687 
4-2631 
200 
4-2767 
4-2711 
220 
4-2931 
4-2875 
A glance at the complete curve for the variation of the specific heat of water with 
temperature reveals at once a most interesting relation. Why should the values 
drop so rapidly from the freezing point and at 37°'5 the complete character of the 
curve change ? There is no discontinuous or sudden change occurring at this point 
that is indicated either in the outward physical state or in the density of the water, 
nor do we see any connection between the curious anomaly in the density curve at 
4° C. and the specific heat at that point. It is evident we have to do here with a 
new, and as yet unexplained, phenomenon. 
The ideas advanced by Rowland in this connection are not, it seems to me, 
altogether correct when he says :—“ However remarkable the fact may be, being the 
first instance of the decrease of the specific heat with rise of temperature, it is no 
more remarkable than the contraction of water to 4°. Indeed, in both cases the 
water hardly seems to have recovered from freezing. The specific heat of melting- 
ice is infinite. Why is it necessary that the sjDecific heat should instantly fall, and 
then recover as the temperature rises ? Is it not more natural to suppose that it 
continues to fall even after the ice is melted, and then to rise again as the specific 
