AND THE MORNING AND EVENING RED. 331 



compare it. When, on the contrary, the orb is near the horizon 

 and has to transmit its light through numerous vesicles, the 

 orange colour obtains a decided predominance. 



Finally, the circumstance that at sunset not only the sun's 

 disc but also a considerable portion of the horizon, and even 

 clouds which float on high appear coloured orange, is easily 

 explained without assuming that these colours are in the first 

 place due to reflexion. As every object which appears white 

 in white light, in orange light must appear orange, the same 

 takes place on the horizon, which, as remarked above, appears 

 whitish by day. 



The explanation of the blue colour of the firmament and the 

 morning and evening red, follow therefore from the assumption 

 of vapour vesicles in the atmosphere, so naturally and simply, 

 that on this account alone the above assumption ought, I think, 

 to be regarded as probable. After having shown however in the 

 foregoing paper that on other grounds the assumption is almost 

 of necessity forced upon us, its easy applicabiUty to the expla- 

 nation of such grand phaenomena furnishes a gratifying corro- 

 boration of the result arrived at. 



[J. T.J 



2 a2 



