40 Mr. C. Chree. 



Table I. 



JLime m 

 inmutes. 



Water. 



JVletiiylateci 

 spirit. 



jrarainn 



nil 

 Oil. 



rr 



_L urpen- 

 tine oil. 



Bisul- 

 phide of 

 carbon. 



Sulphuric 

 acid solu- 

 tion, 

 density 

 12. 



0— I 



606 



416 



133 



170 



510 



587 



*- 1 



386 



327 



136 



137 



270 



422 



1- H 



241 



157 



110 



93 



80 



250 



H— 2 



185 



119 



79 



67 







2— 3 



255 



170 



100-7 



82 







3— 4 



181 



100 



72-1 



43 







4— 5 



138 



79 



50-2 



32 







5— 6 



112 



67 



34-4 



22-6 







6 — 7 



92 



53 



28 -4 



16 6 







7— 8 



74 



38 



17-0 



6 3 







8— 9 



64 



26 



13-8 



•7 







9—10 



58 



21 



11-5 









10—11 





18 



7 3 









11—12 





16 



6-7 









12—13 





15 











13—14 















The times required for the dish to cool from 75° to 30° on water 

 and. on the sulphuric acid solution were almost identical. Excluding 

 the first half minute, the cooling on the solution was slightly but 

 decidedly faster for the first half of the period. In the bisulphide of 

 carbon the experiment was made at a much, lower temperature, which 

 accounts for the comparatively small quantity of heat given to the 

 liquid in the third, half minute. In fact, considering the small 

 temperature excess the rate at which the dish lost heat on the 

 bisulphide was initially extremely rapid. On turpentine for the first 

 few minutes the loss of heat was much faster than on packing ; the 

 rates then began to approach, and after the first nine minutes could 

 not with certainty be said to differ. This coincidence lasted for the 

 next five minutes or more, during which the observations were con- 

 tinued. Excluding the first minute, the cooling on turpentine was 

 very decidedly slower than on any other liquid. This is due to the 

 low conducting power and small specific heat of the liquid, in virtue 

 of which the top layer soon became a sort of barrier to the penetra- 

 tion of the heat. 



The following table gives the density p, and specific heat, c, of the 

 liquids, and the time, t, in minutes, after the heating commenced 

 before the temperature of the platinum wire was rising fastest 



