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except in the mechanical arts, where the powdered deédrzs of their 
frustules, owing to its silicious character, is employed as a polishing 
material. Indirectly, they doubtless contribute to the fertility of 
the soil, and promote the growth of many of the cereals which 
furnish the human family with some of the elements of food. 
“Should we even fail in our attempt to explain the precise 
purposes of the Diatomacez in the economy of being, we may 
rest assured that organisms of such infinite variety have not been 
formed in vain, and that the time we may occupy in the study of 
their functions, or in the admiration of their marvellous symmetry, 
will not have been idly spent, if it enhance our conception of 
Creative Skill, and strengthen our persuasion of the Omnipotent 
Power and Diffusive Energy of the Divine Artificer of Nature.” 
ee eS ee eee 
G, AND T. COWARD, PRINTERS, CARLISLE, 
