EXPERIMENTS OF THOMSON. 83 



Atomic weight. Specific heat. Product. 



Zinc 4-125 0-927 .... 0-383 



Lead 13 0-029 0-377 



Tin 7-25 0-057 .... 0-370 



Copper 4 0-095 0-376 



Bismuth 9 .... 0-040 0-360 



Mercury 12-5 0-029 0-362 



Gold 12-5 0-029 0.373 



Platinum 12 0-310 0-372 



Cobalt 3-25 0.150 .... 0-487 



Phosphorus .. 2 0-385 .... 0-770 



Silver 13-75 0-056 0'770 



Iodine 15-75 0-89 .... 0-401 



Mean of the whole 0-375 



Dr. Thomson maintains, that if the atoms of 

 carbon, silicon, and aluminum were doubled, 

 and those of phosphorus and silver reduced one 

 half, their specific heat would be about the same 

 as the mean of the whole ; and that the other 

 deviations from this average, ought to be referred 

 to inaccurate experiments. But if for the sake 

 of argument we admit his assertion, it would 

 follow that an equivalent of water contains 5*85 

 times more caloric than one of carbon, silicon, or 

 aluminum ; 4*76 times more than an atom of 

 oxygen ; above two and a half times more than 

 one of hydrogen, nitrogen, iodine, or cobalt ; 

 and about 40 per cent, more than one of phos- 

 phorus or silver ; for the specific heat of water is 

 1-125 when multiplied by its atomic weight. And 

 that capacity is no measure of the relative quan- 

 tities of caloric in different bodies, would appear 

 from the experiments of Hay craft, Delarive, and 



