476 CONTENTS OF THE| |„an' Ä 1 E20 ſumm NoTez I1.--PRIMARY CoLouRs,.(pr ».- 4 0 Tie rainbow was in part underſtood before Sir Iſaac. Newton; the ſeven colours were diſcovered by him; Mr. 7 Galton's experiments on colours; manganeſe and lead 50 produce colourlels glaſs. 16 NoTE I11,.--CoLovRED Crovps. um "THE rays refracted by the convexity of the atmoſphere; the particles of air and of water are blue; ſhadow by) means of a candle in the day; halo round the moon in a| an fog; bright ſpot in the cornea of the eye; light from te Cat's eyes in the dark, from a horfe's Eyes In a cavern, ed coloured by the choroid coat within the eye, vo he; NoTE IV.--ComperTs. ſi T arrs of comets from rarified vapour, like northern N lights, from ele&ricity; twenty millions of miles long; 5 Expected comet; 72 comets already deſcribed,]; zan NoTE V.--Suy's Rayvs. D1SPUTE about phlogiſton; the ſün the fountain from whence all phlogiſton is derived; its rays not luminous ll they arrive at our atmoſphere; light owing to their| lai combuſtion with air, whence an unknown acid; the ſun! pe 15 on fire only on its ſurface; the dark ſpots on it are hi exCavations through its luminous cruſt.| NoTE V1.--CENTRAL FIRES, SuN's heat much leſs than that from the fire at the ehe