438 PLINY' B NATURAL HISTORY. [Book XXXVII. 

 CHAP. 50. ASTEOBOLOS. 



Sudines says, that astrobolos^" resembles the eye of a fish in 

 appearance, and that it has a radiant white refulgence when 

 viewed in the sun. 



CHAP. 51. CEKAT7NIA ; FOTJE VARIETIES OF IT. 



Among the white stones also, there is one known as 

 *' ceraunia,"" which absorbs the brilliancy of the stars. It is 

 of a crystalline formation, of a lustrous azure colour, and is a 

 native of Carmania. Zenothemis admits that it is white, but 

 asserts that it has the figure of a blazing star within. Some of 

 them, he says, are dull, in which case it is the custom to steep 

 them for some days in a mixture of nitre and vinegar ; at the 

 end of which period the star makes its appearance, but gradu- 

 ally dies away by the end of as many months. 



Sotacus mentions also two other varieties of ceraunia, one 

 black and the other red ; and he says that they resemble axes 

 in shape. Those which are black and round,^- he says, are 

 looked upon as sacred, and by their assistance cities and fleets 

 are attacked and taken : the name given to them is " baetyli,'* 

 those of an elongated form being known as " cerauniae."^^ They 

 make out also that there is another kind, rarely to be met with, 

 and much in request for the practices of magic, it never being 

 found in any place but one that has been struck by lightning.'* 



CHAP. 52. IRIS ; TWO VARIETIES OF IT. 



The next name mentioned by these authors is that of the 

 stone called "iris;"^® which is found, in a fossil state, in a 

 certain island of the Eed Sea, forty miles distant from the city 



^'^ " Planet-stricken." It is not improbable that this was Cat's-eye, a 

 translucent Chalcedony, presenting a peculiar opalescence, or internal re- 

 flections, when cut en cabochon. The colour is either bright-greenish grey, 

 or else yellow, red, or brownish. 



*^ See Note 8 above. Parisot thinks that these must have been 

 Aerolites or Meteorites. 



*2 Brotero thinks that these were petrified shells, to which the magicians 

 imputed marvellous properties. 



'3 Brotero is of opinion that those were Belemnites, more commonly 

 known as "thunderstones." The reading ''baetyli " is doubtful ; but Par- 

 isot says, on what authority does not appear, that " Betylus " meant •' Great 

 father," and that this name, as well as *' Abaddir" of similar significa- 

 tion, was given by magicians to aerolites or meteorites used in their en- 

 shantraents. h A meteoric stone or aerolite, evidently. 



^' " Rainbow." Opinion seems divided as to whether this is Hyalin 



