110 EXPLORED BY SCIENCE. 



and formed an inclined plain towards the centre, about six feet deep, 

 which I attributed to the action of the wind. I approached at first 

 with the utmost precaution, in order to examine the sand, and found 

 it to be almost impalpable. I cast my plumb-lead as far as I could ; 

 it disappeared immediately ; however, the rapidity with which the 

 rope shortened gradually diminished ; in five minutes, it had wholly 

 disappeared." 



Baron de Wrede has made no attempt to account for this strange 

 phenomenon, which is not, I may add, peculiar to Arabia. The late 

 Doctor Cloquet, who for many years acted as chief physician to the 

 Shah of Persia, relates that he had seen similar gulfs in the great 

 Salt Desert, which he considered to occupy the place of lakes suddenly 

 vanished. This hypothesis is certainly admissible, and perhaps very 

 probable ; but while in some degree explaining the existence of these 

 abysses of sand, it raises fresh questions which are by no means 

 easily answered ; for instance, why have these lakes disappeared, and 

 why have they been replaced by this impalpable and incoherent dust 

 in which heavy bodies sink as in a void ? 



Consider, moreover, the remarks made by Doctor Cloquet in a 

 letter addressed in 1851 to the Academy of Medicine at Paris : 



" At fifteen parasangs from Teheran,* commences the Salt Desert, 

 which, from east to west, extends to the very frontiers of India. 

 This immense basin, eastward, has no other limits than the horizon ; 

 to the west, to the north, to the south, it is bounded by hills of sand 

 which completely represent the Dunes of France, The soil, of a fawn- 

 coloured yellow, is composed of clay and sand, exactly resembling the 

 mud which occupies the bottom of a dried-up basin. It is said that 

 at many points a man on horseback will disappear without his 

 body being ever again disco vered.-j- I have seen one of these places, 

 near Sivas ; the soil is everywhere impregnated with salt mingled 



* A parasang varies in length ; in some parts of Persia it measures thirty, in others fifty 

 furlongs. 



t Such quicksands are found at some parts of the British coast, and the reader will 

 remember that in one of them occurs the catastrophe of Scott's romance, ' The Bride of 

 Lammermoor." 



