4Q4 PHILOSOHHTCAL TRANSACTIONS. [ANNO 1784. 



The intention of previously letting in some dephlogisticated air in the last 2 

 experiments was, that the condensed liquor was thus expected to become more 

 acid, as proved actually to be the case In the first of these 1 experiments, in 

 order that the air to be exploded should be as free as possible from common air, 

 the globe was first filled with a mixture of dephlogisticated and inflammable air ; 

 it was then exhausted, and the air to be exploded let in ; by which means, though 

 the globe was not perfectly exhausted, very little common air could be left in it. 

 In the first set of experiments this circumstance was not attended to, and the 

 purity of the dephlogisticated air was forgot to be examined in both sets. 



From what has been said there seems the utmost reason to think, that dephlo- 

 gisticated air is only water deprived of its phlogiston, and that inflammable air, 

 as was before said, is either phlogisticated water, or else pure phlogiston ; but in 

 all probability the former. 



As Mr. Watt, in a paper lately read before this Society, supposes water to 

 consist of dephlogisticated air and phlogiston deprived of part of their latent 

 heat, whereas I take no notice of the latter circumstance, it may be proper to 

 mention in a few words the reason of this apparent difference between us. If 

 there be any such thing as elementary heat, it must be allowed that what 

 Mr. Watt says is true ; but by the same rule we ought to say, that the diluted 

 mineral acids consist of the concentrated acids united to water and deprived of 

 part of their latent heat ; that solutions of sal ammoniac, and most other neu- 

 tral salts, consist of the salt united to water and elementary heat ; and a similar 

 language ought to be used in speaking of almost all chemical combinations, as 

 there are very few which are not attended with some increase or diminution of 

 heat. Now I have chosen to avoid this form of speaking, both because I think 

 it more likely that there is no such thing as elementary heat, and because saying 

 so in this instance, without using similar expressions in speaking of other che- 

 mical unions, would be improper, and would lead to false ideas ; and it may 

 even admit of doubt, whether the doing it in general would not cause more 

 trouble and perplexity than it is worth. 



There is the utmost reason to think, that dephlogisticated and phlogisticated 

 air, as M. Lavoisier and Scheele suppose, are quite distinct substances, and not 

 differing only in their degree of phlogistication ; and that common air is a mix- 

 ture of the two ; for if the dephlogisticated air is pretty pure, almost the whole 

 of it loses its elasticity by phlogistication, and, as appears by the foregoing expe- 

 riments, is turned into water, instead of being converted into phlogisticated air. 

 In most of the foregoing experiments, at least -f!j of the whole was turned into 

 water; and by treating some dephlogisticated air with liver of sulphur, I have 

 reduced it to less than ^V °f its original bulk, and other persons, I believe, have 

 reduced it to a still less bulk ; so that there seems the utmost reason to suppose, 



