Royal Insiiluiion. 7h 



Bideving its state as that of infancy, rather than of matu- 

 rity ; but that he was now happy to be able to say, that the 

 time was arrived when some principles of chemical philo- 

 sophy at least might be considered as fixed, and some im- 

 portant results anticipated; that it had gained relations lo 

 the doctrines of quantity, and its experiments were capable 

 of being submitted lo those laws of calculation which can- 

 not deceive, and which had already produced such grand 

 results in their application to astronomy. 



That if the substances belonging lo our globe are con- 

 stantly undergoing changes in their forms and iheir sensible 

 qualities, and one variety of matter is, as it were, trans- 

 n)uted into another, such changes, Vi'helher natural or ar- 

 tificial, slowly or rapidly performed, are called chemicnl. 

 The object of cheuiical philosophy is to ascertain their 

 causes, and to discover the laws by which they are govern- 

 ed. The ends of tliis branch of knowledge, said the Pro- 

 fessor, are the apphcations of natural substances to new 

 uses, for increasing the comforts and enjoymenls of man, 

 and the denionstrat)on of the order, design, and intclligfnt 

 arrangements, of the, system of the earth. 



In taking an extended view of (he plan of the lectures, 

 Mr. Davy said, he should first consider the active powers 

 producing the phaenomenon of chemical change, and afte* 

 vvards the substances on which they operate. The expan- 

 sive power or heat, chemical and electrical attraction, are 

 the great causes of decomposiiion and combination. In 

 discussing the doctrines of heat, he said he should compare 

 the mechanical hypothesis of its consisting in motion of 

 the particles of bodies with the idea of its being a specific 

 kind. — The first opinion was sanctioned by the authority 

 of the greatest phdosophers of this country, is e()ually ap- 

 plicable to the explanation of the phasnomenon, and in- 

 volves the supposition of fewer unknown causes. — Chemi- 

 cal attraction, he said, he should consider as a definite 

 power, combining I)odies in definite proportions, capable 

 of being expressed by numbers. Electrical attraction pro- 

 duced many of the same eflects as chemical attraction; and 

 electricity, as exlnbitcd by the \'oltaic apparatus, is capa- 

 ble of being n)ade a general uistrtunent of decomposition. 

 Mr. Davy referred to the extrnoidiuary en"ects produced by 

 this wonderfid invention, which, he said, had done as nuich 

 for the higher departiTients of cheniisiry as the air (lump 

 for pneumatics, the microscoi)e for natural liislory, and 

 the telescope ior astronomy; and which had not only pro- 

 jlueed new views in the. science lo which it )iarticularly 



belonged, 



