4;26 Dr. Beke on the Alluvia of Babylonia a7id Chaldcca. 



ness and ingenuity, is Brandes, in the article Abendrothe 

 (evening redness), in Gehier's Physikalisches Worterbuch *. 

 He maintains the colour of the sun, and surrounding clouds, 

 at sunset and sunrise, to be due solely to the colour of pure 

 air, — a doctrine which he supports by many striking argu- 

 ments. The presence of vapours, he observes, is always in- 

 dicated by a dull white, mixed with the azure of the sky, and 

 the complementary colour of that white which should belong 

 to the transmitted ray can never be red. On the contrary, 

 he says, the colour of the sun seen directly through clouds, 

 when on the meridian, is always white, and the effect even of 

 so strong a mist as to render his disc easily viewed by the 

 naked eye, is to give it the appearance of a silver plate f. 

 The beauty of the sunset, he further observes, is in exact 

 proportion to the purity of the atmospheric blue during the 

 day ; and the only reason, he asserts, why the sun appears to 

 set red through vapours, is because his light is by them so 

 much diluted that the colour can be more distinctly perceived. 

 The colour of elevated clouds, at some distance from the ho- 

 rizon, he imputes (as Melvili had done) to the great space of 

 air which the light must traverse before it reaches them, and, 

 after doing so, before it falls on the eye. The green colours 

 of the sky he attributes, as Leslie and most other writers have 

 done, to the reflected blue light mixing with the transmitted 

 orange. This theory was never so ably handled. 

 [To be continued.] 



LXIV. On the Alluvia of Bahyloriia ajid Chaldcca. By 

 Charles T. Beke, Ph. Z)., F.S.A. 



To the Editors of the Philosophical Magazine and Journal. 



Gentlemen, 

 TT is now two years since I last addressed you on the ad- 

 -*- vance of the land at the head of the Persian Gulf J; I am 

 now induced to revert to the subject by the recent publication 

 of Mr. Ainsworth's " Researches in Assyria, Babylonia, and 

 Chaldaea," (London, 1838), in which work are given the geo- 

 logical results of the Euphrates Expedition under the able 

 conduct of Colonel Chesney. 



Without going into the details of Mr. Ainsworth's investi- 

 gations, it is sufficient to say that he determines " so far, the 



• Vol. i. p. 4. &c. 182.5. 



t Gehier's Physikalisches Worterbuch, vol. i. p. 6, Note. 



X See Lond. and Edinb. Phil. Mag. for July, 1837; voi. xi. p. 66. 



