or EGYPT. 39 



2. A fine clay, which is found chiefly in caves only acces- 

 sible to the river-water at high tide. This might naturally 

 be expected to contain bones and throw some further light 

 upon our knowledge of the animals which inhabited the 

 country at a former period, as it would certainly do in a 

 damper climate ; but, owing to the dryness of the atmosphere, 

 the bones no doubt decompose before they can become buried 

 in these beds, which must take a long time in forming, as 

 they are not assisted by any dropping from the ceilings, but 

 are entirely composed of the fine mud brought there during 

 the short period of high Nile. This clay is extremely useful, 

 being employed for the manufacture of the " goulos," or 

 water-bottles, so much used in Egypt. 



