380 Dr. Ure’s new experimental researches 
square of their temperature, is totally inapplicable to mercury, 
the inference relative to the thermometric mean between 32 0 
and 212 0 cannot be allowed. But let us examine, on their 
own merits, the preceding arguments against Dr. Crawford 
and De Luc’s verification of the mean temperature between 
that of freezing and boiling water. 
The reasoning derives its sole force from the assumption, 
that the capacity of water for heat, increases as its tempera- 
ture is raised. There is adduced, however, no fact in the least 
decisive on this main point. What analogy is there between 
the entire change of form and constitution suffered by an incon- 
densible liquid, on becoming an elastic vapour, and the pro- 
gressive heating of the liquid itself? Or, although dilute 
sulphuric acid and other liquids should increase in their 
specific caloric on being heated, which however has not been 
satisfactorily demonstrated, are we to assert that water must 
do so too ? It is a matter of surprize to me, that a philosopher 
of Mr. Dalton’s judgement and acuteness should have 
pressed such inconclusive analogies into his service. He 
knew well that water is endowed with some curious peculia- 
rities, when compared with other liquids, or anomalies, as we 
idly stile them ; for they constitute no anomaly in nature, but 
wisely fit water for performing the important functions 
assigned to it in the economy of our globe. 
In a series of experiments, carefully conducted on the 
relative capacities for heat, of water, sulphuric acid, oil of 
turpentine, and spermaceti oil, published in my Essay on 
hydrochloric acid and the chlorides ; it seems to be directly 
demonstrated that the specific heat of water does not increase , 
but actually diminishes, and that very conspicuously, as its 
