CHAPTER XIII 



CONSTITUTION OF MATTER CHEMISTRY THE ELE- 

 MENTS PHLOGISTON THEORY OXYGEN AND 

 COMBUSTION. 



IN the short sketch given of the history of Al- 

 chemy it was noticed that this pseudo-science, vain 

 in its purpose and futile in its ends, had yet en- 

 riched the world with many discoveries of the proper- 

 ties of matter that otherwise would long have re- 

 mained unknown. This knowledge, though, was a 

 heterogeneous mass of disconnected, unsystematized 

 facts, imperfectly understood, and filled with mis- 

 takes and errors. The idea that the base of all sub- 

 stances was one the formless matter, inert and 

 without properties; in itself ignoble and of degrad- 

 ing nature, unworthy of study or examination was 

 universally held. It still exists, often unconsciously, 

 in the minds of many metaphysicians and theologians. 

 The word " Materialistic " is still a term of oppro- 

 brium. The four elements earth, water, air and fire 

 were thought to be the cause of the " accidents of the 

 substance to which its respective properties were at- 

 ii 161 



