ANTOINE LAURENT LAVOISIER 133 

 But, if the base of the air was held in sokition by the fire matter, in 

 proportion as this base combined with the metal, the fire matter should 

 become free and produce, in freeing itself, flame and light. You 

 understand that the more speedy the calcination of the metal, that is 

 to say, the more fixation of the air takes place in a given time, the 

 more fire matter will be liberated, and, consequently, the more marked 

 and obvious the combustion will be. 



I might apply this theory successively to all combustions, but as I 

 shall have frequent occasion to return to this subject, I will content 

 myself at this time with these general illustrations. So, to resume, 

 the air is composed, according to my idea, of fire matter as a dis- 

 solvent combined with a substance which serves it as a base, and 

 which in some way neutralizes it; whenever a substance for which it 

 has a greater affinity is brought into contact with this base, it leaves 

 its solvent; then the fire-substance regains its rights, its properties, 

 and appears to our eyes with heat, flame and light. 



Pure air, the dephlogisticated air of Mr. Priestley, is then, accord- 

 ing to this opinion, the real combustible body, and perhaps the only 

 one of that nature, and it is seen that it is no longer necessary, in 

 order to explain the phenomena of combustion, to suppose that there 

 exists a large quantity of fire fixed in all the substances which we call 

 combustible, but that it is very probable, on the contrary, that ver\' 

 little of it exists in metals, in sulphur, phosphorus, and in most of 

 the very solid, heavy and compact bodies, and, perhaps even that there 

 exists in these substances only free fire matter, in virtue of the prop- 

 erty which this matter has of putting itself in equilibrium with all sur- 

 rounding bodies. 



Another striking reflection which comes to the support of the pre- 

 ceding ones, is that almost all substances may exist in three different 

 states : under a solid form, under a liquid form, that is to say melted, 

 or in the state of air or vapor. These three states depend solely on 

 the quantity, more or less, of fire matter with which these substances 

 are interpenetrated and with which they are combined. Fluidity, 

 vaporization, elasticity, are then properties characteristic of the 

 presence of fire and of a great abundance of fire ; solidity, compact- 

 ness, on the contrary, are evidences of its absence. By so much then 



