^•ix. 



I. 



2. 



•b 



^com 



*vhi 



eof 



I' 



'tes. 



IS 



Wer 



getable 



) 



nu. 



me 



sill 



I 



"^tioiis of 



0" which 



pigeons, 

 -> owing to 



"■vatlons and 

 le colours of 

 of the leaves 



iJi\ or fitua- 



-om the lux- 

 me lit, molf- 



andof 

 of the 



vers 



) 



ution 



ley 



an 



have n- 



d of heat ; 

 ts in general, 



their pe 



ersor 



foliags 



-1 



es 



?i 



chen^ii^O' 

 cotton- 



oloiin"5 



as 



It 



ec 



'Thus 



on 



rives 



rrioi 



■Mi 



J 



liu^" 



Sect. XIX. 1.2. 



OF FLOWERS. 



537 



f 



fpread upon the ground fS 



'^^^ 



th 



oxy 



thus detached wh 



"'^ms to decompofe the water, and 

 m5 the linen. The etiolation of 



blanching of living vegetables on th 



e 



y 



feeras to originate 



from th 



gen ; 



f th 



fu 



n s 



to 



ht to convert into gas the^fluid oxy 



hich, by difTolving their colouring naattei 



d forming 



new and perhaps taftelefs acid 



d 



P 



th 



of colour. H 



hich vegetables perfpire in the funfhine, becomes hyp 



oxygenated, which has much puzzled philofophers tc 

 and the oxygen rifes from it without decompofing it 

 circumftance is evinced by the total abfence of tl 



■ 



gen, which fo powerfully afFe£ls our noftrils, v 

 water is thrown on burning coals. 



fo 



h 



laft 



h 



fmell of hydro- 



;n a fpoonful of 



Now as pi 

 ment, moifti; 



air 



hich grow lefs vigoroufly from defect of nu 

 or warmth, may acquire or polTefs lefs oxy 



1 



to diffolve their colouring matter, their flrudure may approach to- 

 wards that of dead vegetables ; and hence they may become bleached 



inftead of coloured 

 thofe parts where 



the influence of the fun's light, efpecially 



th 



vital fundi 



gour 



fo an etiolated vesetabl 



o 



ns are performed with lefs vi- 

 blanched plant of celery, apium 



graveolens, becomes green in a few day 



hen expofed to the light 



d 



d 



h 



o 



f deprived of life, and expofed to th 



funfhine and d 



The immediate caufe of the various colours of fome flowers 



of 



^ 



poppies, might be a fubje6l 



f curious inveftig 



I once fup 



pofed, that the thinnefs of the pellicle of fome flowers might 



fion them to refledt diffe 



as IS 



fee 



n on 



d 



ropp 



of 



from 



drop 



bridge on the water below on a bright day 



B 



CO 



thus produced vary with the fituation of the obferver, in refpe£l 



the obliquity 



to 



of reflecl 



hich they are feen 



d 



thence variable with every motion of them, as thofe colours feen 



foap- bubble 



d on mother- pearl, and on the Labradore-ftone 



d on fome filks. For thofe colours depend on the thinnefs of the 



■• 



3Z 



jefle (fling 



