352 New Out lines of Chemical Philosophy* 



concerned in the experiment, it remains to show how the two 

 gases are formed. 



The three circumstances contained in this experiment admit 

 only of two coinbiiiations, as the elements in this instance do 

 not combine — for where thev do they cease to act on matter. 

 Hence tliermogen and water form oxygen gas, photogen and 

 water form hydrogen gas — water being the only gravitating 

 matter. 



But sU])uose for a moment tliat water were a compound of 

 oxygen and hydrogen, then the circumstances ox natural things 

 vrculd be 4, and their combinations 2 x2 = 4. Thermogen and 

 jjliotogen being united to the supposed component parts of water, 

 each combination would produce a new compound ; thus, 



Thermogen combined with the oxygen of the water, would 

 form a compound (c). Thermogen combined with the hydro- 

 gen of the water would form another compound (b). Photogen 

 combined with the oxygen of the water would form a third com- 

 pound {c). And photogen combined with the hydrogen of the 

 water would form a fourth compound {d). 



But in tlie eriperiment of the decomposition of water, we have 

 oidy two compounds, oxygen and hydrogen gases ; consequently 

 the supposition is erroneous. 



In the decomposition of water there can be no more than 

 three circumstances concerned in the experiment to produce the 

 two gases ; therefore, if water be a compound of oxygen and 

 hydrogen, the electric fluid (as it is called) is a simple element j 

 but ii' th.e electric fiuid be composed of two elements, then it fol- 

 lows that water is a simple body. 



Now, as it has been proved by the most satisfactory experi- 

 ments that the electric fluid is composed of two invisible ele- 

 ments^, water is imquestionably a simple body, and the only 

 ponderable base of the two gases. 



This is not a new conclusion; but it is derived from principles 

 very different from those made use of by Dr. Priestley and other 

 eminent philciophers. Dr. Priestley proved by several chemical 

 experiments, that water is a simple body, and supported the 

 opinion that it is the only ponderable base of oxygen and hy- 

 drogen gases and other aerial fluids. 



The supposed discovery that water is a compound body, re- 

 ceived its chief su) port from the following experiment. INI. Ber- 

 thollet and his associates burned together fifteen grains of in- 

 flammable air and eighty-ftve of vital air, and obtained exactly 

 (jne hundred grains of water ; in which by decomposition they 

 found again the sair;c principles, and in the same proportion. 



* n.'il.Mag. vol. xliii. p. 'J81. 



Now 



