COMPOSITION OF SEA-WATER. 103 



employ the same substance to form their own 

 abodes. The structure of a vast number and 

 variety of these creatures is expressly adapted to 

 secrete lime and form it into shells of every form 

 and colour, and in many instances of great mag- 

 nitude. The external covering of all the Crustacea 

 and considerable portions of the internal structure 

 of other marine animals either inhabiting our 

 sea-shores or living in deep water 3 are formed of 

 lime thus marvellously extracted from the element 

 they inhabit. In all cases where such shelly 

 coverings are found, they are absolutely requisite 

 not only to the enjoyment, but to the very 

 existence, of the creatures whom they enclose. 

 And thus we perceive that the constitution of the 

 sea-water is designed by its Divine originator to 

 minister to the wants of an infinite number and 

 variety of forms, all endowed with the mysterious 

 principle of life, and all possessed of degrees of 

 happiness and modes of enjoyment adapted to 

 their condition. 



H 4 



