7 
44 On Specific Heat. 
so that +4, of a degree could be distinguished. After bestowing 
the utmost pains in repeating the experiments during a period of 
nearly two months, I found that the only way of removing the 
little discrepancies, which crept in between contiguous measures, 
was to adopt the astronomical plan of multiplying observations 
and deducing truth from the mean. It is essential to heat with 
extreme slowness and circumspection, the vessels, A, B, C. One 
repetition of the experiment occupies on an average 7 hours. 
. [To be continued. ] 
X. On Specific Heat. By Mr. Josupu Lucxcock, of Bir- 
mingham. 
Mecu ingenuity and patient research have been displayed on 
the subject of Specific Heat ; the thermometer, the meltings of 
ice, and the times of cooling heated substances, have been the 
basis of these calculations ; and imposing algebraical formule 
have been brought in aid, to give to them the air of demonstra- 
tions: the results, however, are unsatisfactory ; for in the attempts 
to fix the natural zero, or point of absolute privation of heat, 
some have placed it at 900° below the scale of Fahrenheit, whilst 
others have depressed it to 11000°. 
This has principally arisen from a want of precision in our 
ideas, from the want of adefinition of heat. My Essay on the 
atomical philosophy, published by Longman and Co., has been 
some time before the public; wherein I have endeavoured to set 
this matter right. I have identified the matter of heat with the 
electric fluid, that it is the element of fluidity, and to which I 
have given the name of Fluidium ; because of the meagreness of 
the terms applied to the subject ; such as heat of capacity, or 
specific heat; heat of transmission, or thermometric heat; creating 
a confusion of ideas in the mind, of hot heat and cold heat: the 
term Fluidium may well express latent heat, or heat of capacity, 
or specific heat; and the term Heat will well express its trans- 
mission by the means of chemical or electrical agency; and in 
which sense I shall use the terms, considering Fluidium as a sub- 
stance, and Heat as a quality. 
Sir H. Davy, speaking of the production of light and heat, 
very happily expresses himself ‘ that it is a general result of the 
actions of any substances possessed of strong chemical attrac- 
tions, or different electrical relations, and that it takes place in 
all cases in which an intense and violent motion can be conceived 
to be communicated to the corpuscles of bodies :’ and he might 
have added that there can be no chemical attraction, no chemi- 
cal action whatever, without electrical relations, without the aid 
of 
