MY GARDEN. 



The water issuing from these cracks is as clear as crystal, and 

 charged with carbonic acid. It has the temperature of 52, which is 

 warm in winter, and delightfully cool to our senses in summer. It 

 contains sufficient saline and calcareous matter to make it palatable, 

 and hereafter I shall point out that these cracks give to us the 

 inestimable blessing of the River Wandle. 



There is abundant evidence to prove that chalk was formed at the 

 bottom of an ocean. Chalk consists, chemically, of carbonate of lime. 

 It is amorphous, and no power of the microscope reveals structure. 

 This is very curious, because chalk deposited by Clark's process is 

 invariably crystalline. 



Chalk appears to result chiefly from the decay of the lower animals, 

 and it is a most interesting discovery of modern times that another 

 deposit of chalk is now being formed at the bottom of the Atlantic 

 Ocean and Mediterranean Sea. Innumerable foraminifera live in these 

 seas (fig. 22) ; these die and fall to the bottom, and it is now a 



4- 5 6 7 



Fie;. 27. Foraminifera ancient). 



FIG. 22. Foraminifera (recent). 



1. Planorbulina Ungeriana. 4. Rotalia Beccarii. 



2. Trilochulina tricarinata. 5. Nonionina turgida. 



3. Globigerina bulloides. 



universally recognized fact that by their decay a bed of chalk is being 

 formed for future ages. Corals however, besides foraminifera, contribute 

 to the formation of chalk. 



I asked Mr. Groves, who has great experience in microscopic objects, 

 to examine the chalk of our district to determine the foraminifera 

 which it contained. He discovered that little pockets in the flints 

 yielded the greater number, and from his investigations he found 

 many of the shells of the foraminifera to be in a fair state of pre- 

 servation. He found numerous forms of the Rotaline series (i, fig. 21). 



