A SUMMER RAMBLE AMONG THE HEBRIDES. 63 



of an eastern annalist, the Emperor Baber, who flourished 

 late in the fifteenth century, and, like Caesar, conquered and 

 recorded his conquests, still survives. He describes it as the 

 Khwaja Reg-Rawan, " a small hill, in which there is a line 

 of sandy ground reaching from the top to the bottom," from 

 which there " issues in the summer season the sound of drums 

 and nagarets." In connection with the fact that the musical 

 sand of Eigg is composed of a disintegrated sandstone of the 

 Oolite, it is not quite unworthy of notice that sandstone and 

 lime enter into the composition of the hill of Reg-Rawan, 

 that the district in which the hill is situated is not a sandy 

 one, and that its slope of sonorous sand seems as if it had 

 issued from its side. These various circumstances, taken to- 

 gether, lead to the inference that the sand may have originated 

 in the decomposition of the rock beneath. It is further no- 

 ticeable, that the Jabel Nakous is composed of a white friable 

 sandstone, resembling that of the white friable bed of the 

 Bay of Laig, and that it belongs to nearly the same geologi- 

 cal era. I owe to the kindness of Dr Wilson of Bombay, 

 two specimens which he picked up in Arabia Petrsea, of spines 

 of Cidarites of the mace-formed type so common in the Chalk 

 and Oolite, but so rare in the older formations. Dr Wilson 

 informs me that they are of frequent occurrence in the desert 

 of Arabia Petrsea, where they are termed by the Arabs pe- 

 trified olives ; that nummulites are also abundant in the dis- 

 trict ; and that the various secondary rocks he examined in 

 his route through it seem to belong to the Cretaceous group. 

 It appears not improbable, therefore, that all the sonorous 

 sand in the world yet discovered is formed, like that of Eigg, 

 of disintegrated sandstone ; and at least two-thirds of it of 

 the disintegrated sandstone of secondary formations, newer 

 than the Lias. But how it should be at all sonorous, what- 

 ever its age or origin, seems yet to be discovered. There are 

 few substances that appear worse suited than sand to com- 



