New Outlines of Chemical Philosophy. 353 



Now this verv experiment proves that water contains nothing 

 that is combustible; for of all combustible bodies vvhen burned 

 with some substance containing the element of heat (oxygen), the 

 inflammable matter is converted into Hght, the oxygen into heat^ 

 and what remains at the end of the process is an incombustible 

 substance. Had the water been a compound of two gases perfectly 

 combustible, according to the French doctrine, they would have 

 been wholly converted into light and heat, and no water would 

 have remained ; or, had any part of the water been combustible^ 

 the weight of the water remaining at the end of the experiment 

 would have been so much less than the weight of the two gases. 

 And the two elements of combustion, being imponderable, add 

 nothing to the weight of the two gases ; and hence the reason 

 that the weight of the water found at the end of the CAperiment 

 was exactly equal to the weight of the two gases. 



Since light, heat, and an incombustible substance are pro-» 

 duced by burning together the two gases, it is necessary that 

 combustion should be investigated before the composition of 

 water can be understood from this experiment. 



The learned translator of Haiiy's Treatise on Natural Philo- 

 sophy* observes, that '^ the subject of combustion is a very dif- 

 ficult one, respecting which opinions are still afloat ; the theory 

 of the eminent yet unfortunate Lavoisier, though adopted by 

 Haiiy, and indeed by the generality of chemists, both continental 

 and English, is far from satisfactory." 



And after giving some account of the theories of INI. Lavoisier 

 and Dr. Thomson, he further observes: " still it must be acknow- 

 ledged that this is a very obscure subject ; the reader would, 

 therefore, do well, before he forms a decisive opinion, to trace 

 the progressive improvement of the theory in the hands of Boyle, 

 Hooke, Mayow, Beccher, Stahl, Sc'.ieele, Kirwan, Black, Craw- 

 ford, Lavoisier, Brugnatelli, and Thomson, with a view to which 

 he may advantageously consult the article Comhustioyi in Dr. 

 Gregory's Encycloptedia, and in the Supplement to the Encyclo- 

 paedia Britannica; Robisou's Life of Dr. Black; the Edinburgh 

 Review, No. 5 ; Nicholson's Journal, N. S. vol. ii ; Nicholson's 

 Chemistry; and Thomson's Chemistryf." Hence it appears 

 that the French academicians were totally unaciiuainted with 

 combustion, when tbey made their experiments from which they 

 deduced the conclusion, that v/atcr is a compound body. 



As the term phlogiston has occasioned much controversy, it 

 may be necessary to remember what has been stated in a former 

 paper I ; that the imponderable element of hydrogen gas of La- 

 voisier, the phlogiston of Stahl, Scheele, and Priestley; the ne- 



• Publislii d io 1807. t '^ec also Phil. Mag. vol. xiii. p. 3G8, for 



a inorp ro.-ent tliffirv. t Pliil- Mag, vol. xlvl, p. 430. 



Vol.49.No.229. Afffy 1817. Z gative 



