38 THE UNIVERSE. 



soil of the desert only consists of a thick bed of nummulites, 

 in which the foot of the traveller and the camel slipped and 

 sank deep at every step. 



Paris is, as we have said, built solely of shells; this is 

 also the case with the Sphinx and the celebrated Pyramids 

 of Egjrpt. The immense courses of the latter, neither the 

 transportation nor the raising of which to such a vast 

 height is explained by art, were brought from the Arabian 

 chain, and are composed solely of nummulites. Many of 

 these exactly resemble lentils in their form and size ; this 

 coincidence has given rise to strange mistakes. Time, 

 gnawing the surface of these gigantic monuments, has 

 gathered enormous masses at their bases, where they im- 

 pede the footsteps of the traveller. In the time of Strabo 

 it was maintained that these were the remains of seeds 

 used as food by the ancient workmen, who had abandoned 

 them, and which had fossilized by the action of time. Biit 

 the Greek geographer refuted this vulgar tradition, and in 

 his description of Egj^t he classes the nummulites among 

 the petrifactions, calling to mind that in his own country, 

 the Pontus, there Avere hills full of tuff" stones similar to 

 lentils. 



The stone of Laon, often employed in our buildings, is 

 equally composed of masses of nummulites. 



We have said that extremes are met with everywhere; 

 Ave have already foiind them among the molluscs, creatures 

 disinherited, as it Avere, by creation. We have spoken of 

 microscopic shells; Ave proceed to speak of some colossal 

 ones. 



One of these in particular has acquired a certain celebrity 

 on account of its size and the peculiar use to Avhich it has 

 been put. It is the gigantic Tridacna, commonly knoAvn 

 as the " font," because it is sometimes employed in our 



