xii CONTENTS. 



Page 

 Colour denotes properties and constitution, combination of light with f ^ 



steel . . 81 



Each ray changing its qualities Priestley Boyle . . .82 



Oxygen discharged by light ignition in ammonical gas . . 83 



Constituents of light in alkalies and acids, their effects on vegetable 



juices . . .84 



On vegetation . . . . 86 



j ron traces of compound nature, analysis of, by Dr. Thompson . 87 



Chlorine destroys colour of indigo, as does the yellow ray imparted by ^ 

 the Voltaic circle . . . . .88 



Sulphur blood, arterial and venous Priest ley, Hazzenfratz, Davy, 



Dr. Beddoes, Fourcroy, Dr. Thompson . . . .89 



Elements of the ancients . . . . - .90 



Elements of the moderns, 54 in number test of originality but three 



are found to afford it . . . . .91 



Consequent doubt of correctness in denominating the 51 other bodies 



undecompound . . . . . .92 



Order of polarity to constitute light Chemical qualities of terrestrial 

 light differ from those of the solar beam carbon in the former, 

 nitrogen in the latter why gold resists the one, and submits to 

 the other application of oxy-hydrogen blow-pipe with lime, may 

 afford a solvent volatilizing power . . . .93 



Investigation importuned not establishment of hypothetical views . 94 

 Absorption and discharge of light without combustion Beccaria 



Canton's phosphorus composition phenomena of phosphori . 95 

 Oxygen derived from light Priestley, Ingenhouze, Scheele, Beetholet 96 

 Supporters of combustion bodies in a state of ignition extinguished 



by hydrogen gas pure carbon charcoal . . .97 



Carburetted hydrogen when mixed with oxygen gas in certain propor- 

 tion, combustion is extinguished carbonic acid gas why incom- 

 bustible . . . . . .98 



Electrical machine surrounded by carbonic acid gas greater excite- 

 ment than when insulated in hydrogen gas. Hypothetical ar- 

 rangements of composition, exactitude of polarity essential sup- 

 porters and combustibles form incombustibles . . .99 

 Carbonic oxide purplish blue flame order of polarity imputable to 



inflammables and incombustibles . . . .100 



Combination binary and ternary transposition of positive pole on the 

 compound. Spherical atom lateral poles inert, unless in exces- 

 sive cohesion . . . . . . .101 



Intensity of fixation governed by polar arrangements nitrogen not 



incombustible, yet so termed four-fifths of the atmosphere . 102 



