of Edinburgh, Session 1881-82. 
809 
galvanometer very sensitive, I failed to get any deflection ; I have 
since found that the brass line lies very near the lead line, so that 
this result agrees with the diagram. 
The following table (V.) gives the ratios of the Peltier effect at 
the lower temperature to that at the higher temperature for the 
various pairs of metals — 1st, according to these experiments ; 2nd, 
according to Professor Tait’s thermo-electric diagram : — 
Metals. 
Lower Temp. 
Higher Temp. 
Campbell. 
Tait. 
Fe-Pb 
20° C. 
85° C. 
•991 
1-02 
Fe- Arg. ... 
20° 
93° 
•86 
•803 
Pb-Ag (Standard).. 
22° -5 
98° -5 
•582 
•545 
Fe-Zn 
23° -8 
99° 
1-43 
1-36 
It should be remarked that the battery used was not the same 
for all the pairs of metals ; sometimes one Bunsen cell, sometimes 
three, were used. Hence these experiments give no means of com- 
paring the Peltier effect for different pairs. 
3. On the Lowering of the Maximum Density Point of 
Water by Pressure. By Professor D. H. Marshall, Pro- 
fessor C. Michie Smith, and E. T. Omond, Esq. 
At the meeting of 17th April we gave an account of some experi- 
ments made at the request of Professor Tait on the lowering of the 
maximum density point of water by pressure. We called the 
notice we gave of these experiments at that time preliminary, 
because we were anxious to perform further experiments to satisfy 
ourselves thoroughly of the correctness of the important conclusions 
then arrived at. We desire now to state that we have repeated 
these experiments with some slight improvements in experimental 
details, and at different temperatures, and are glad to state to the 
Society that our further experiments quite bear out the conclusions 
previously arrived .at. The following will suffice to show the nature 
of any day’s experiment. [For description of the apparatus used, 
Ac., see ante , p. 626.] 
