On Chemical Philosophy. 343 



"avd lectures on this sii1)ject, they confine their fittention so ex- 

 clusivelv to the phjEnonieini of heat and fla;ne, as in the most 

 unequivocal manner proves they conceive these features and ap- 

 pearances characterize its proper form and nature: that, in fact; 

 caloric abstractly considered is something in its own nature hot 

 and fiery. 



This I conceive, as will be evident, is an erroneous and very 

 imperfect concoption of its nature and of its actions: and hence, 

 on this subject there has been so much controversy ap.d con- 

 fusion of opinion. As, for instance. From whence is it derived > 

 Whither does it proceed? Why is there frequently heat without 

 light? Why, again, do thev generally appear together? Whether 

 are they in reality separate and distinct powers ? Many contend 

 thev are mere properties of matter, and nothing in themselves. 

 Some, that thev are only the effects which the vibratory motio?i 

 of the particles of matter produces. And what appears to me 

 verv curious, before any one of these questions is answered, al- 

 most all our modern philosophers have either been exertin* 

 themselves with ail their might to prove, or have admitted a» 

 proved, that heat and light, while they have a repulsion for their 

 own particles, possess not only an attraction for each ctlier, but 

 for all kinds of matter; and this is said even by some who at 

 the same tin^.e affirm, that boat and light are nothing in them- 

 selves, mere properties of matter, or the mere vibration of it* 

 particles. Nor have these various opinions and contendln* 

 theor"es at all diminished since the Lavoisierian theory of com- 

 bustion; protn!l^ in mv opinion most fnllv, that the views i.f the 

 nature of this power and of its actnms, are still crrone(ms and im- 

 perfect: and in fact it is now admitted, tiiat this theory does not ac- 

 count for the heat and flame which appear in many instances ; an4 

 I conceive it is very imperfect in its application to all of them. 



Now, from the theory ah-eady briefly, and consequently from 

 its brevity imperfectly, detailed as it is, it will, I conceive, appear 

 evident, (and I trnst :^till more so when we come to particular 

 detail,) that heat and flame are tlie mere effects and phaenomena 

 which attend the more energetic operations of a power on which 

 every motion, change, effect, and phacnomenon, throughout na- 

 ture depend : and though we do not apply the word caloric, a* 

 the can-e of those changes which are more slowly produced, the 

 power and the principles of its operation are the same, differin;!; 

 ijot in kind but in degree, and the nature and circumstances ot 

 its acti()n«. Confounding the difference between that which 

 j'lay be the same in kind i)uc very different in degree, is, on ail 

 '•ubjects, the most frequent cause of error in our conceptions and 

 our reasonings, and, what is worse, in oiu- practice. Perceptible 

 lifat and visible flame are cffecli aiul appearances which, I re- 

 peat, 



