ZODIACAL LIGHT. 139 



1001. Tho first observation of the plienomenon may have 

 been made two or three years prior to this period ; but, not- 

 Withstanding, the merit of having (in the spring of 1683) been 

 the first to investigate the phenomenon in all its relations in 

 space is incontestably due to Dominicus Cassini. The light 

 which he saw at Bologna in 1668, and which was observed 

 at the same time in Persia by the celebrated traveler Char- 

 din (the court astrologers of Ispahan called this light, which 

 had never before been observed, nyzck, a small lance), was 

 not the zodiacal light, as has often been asserted,* but the 



and of the retardation of the extremes of the effects in meteorological 

 processes. It is, however, to be regretted that our Baconian-philosophy- 

 loving author, who was Lord Henry Somerset's chaplain, lell into the 

 same error as Bernard iu de St. Pierre, and regarded the Earth as elon- 

 gated at the poles (see p. 143). At the first, he believes that the Earth 

 was spherical, but supposes that the uninterrupted and increasing addi- 

 tion of layers of ice at both poles has changed its figure ; and that, as the 

 ice is formed from water, the quantity of that liquid is every where 

 diminishing. 



* Domiuicus Cas&iiii (Mem. de I'Acad., t. viii., 1730, p. 188), and 

 Mairan (Aurore Bar., p. 1G), have even maintained that the phenome- 

 non observed in Persia in 1668 was the zodiacal light. Delambre 

 (Hist, de VAstron. Moderne, t. ii., p. 742), in very decided terms, ascribes 

 the discovery of this light to the celebrated traveler Chardin ; but in the 

 Couronnement de Soli man, and in several passages of the narrative of his 

 travels (ed. de Laugles, t. iv., p. 326; t. x., p. 97), he only applies the 

 term ma/.ouk (oyzek), or "petite lance," to "the great and famous 

 comet which appeared over nearly the whole world iu 1668, and whose 

 head was so hidden in the west that it could not be perceived in the 

 horizon of Ispahan" (Atlas du Voyage de Chardin, Tab. iv. ; from the 

 observations at Schiraz). The head or nucleus of the comet was, how- 

 ever, visible hi the Brazils and in India (Pingrc, Cometogr., t. ii., p. 22). 

 Regardhig the conjectured identity of the last great comet of March, 

 1843, with this, which Cassini mistook for the zodiacal light, see Schum.. 

 A*tr. Nachr., 1843, No. 476 and 480. Iu Persian, the term "iilzehi 

 fiteschin" (fiery spears or lances) is also applied to the rays of the ris- 

 ing or setting sun, in the same way as " nayazik," according to Frey- 

 tag's Arabic Lexicon, signifies " stellae cadentes." The comparison of 

 comets to lanca and swords was, however, in the Middle Ages, very 

 common in all languages. The great comet of 1500, which was visible 

 from April to June, was always termed by the Italian writers of that 

 time il Signer Attone (see my Examen Critique de I 1 Hist, de la Gto~ 

 graphic, t. v., p. 80). All the hypotheses that have been advanced to 

 show that Descartes (Cassini, p. 230; Mairan, p. 16), and even Kepler 

 (Delambre, t. i., p. 601), were acquainted with the zodiacal light, ap- 

 pear to me altogether untenable. Descartes (Principe*, iii., art. 13G, 

 137) is very obscure in his remarks on comets, observing that their 

 tails are formed " by oblique rays, which, falling on different parts of 

 the planetary orbs, strike the eye laterally by extraordinary refraction," 

 and that they might be seen morning and evening, " like a long beam," 

 when the Sun is between the comet and the Earth. This passage no 

 morcf refers to the Jodiacal light than those in which Kepler (Epit A* 



