12 GENERAL HISTORY OF 



argillaceous and other earths, contract the forms of sili- 

 ceous slate, porphoretic rocks, &c., present us with 

 geological facts recorded by the Divine truth, the investi- 

 gation of which, by the aid of the microscope, unlike the 

 records of human wisdom, biassed by prejudice or alloyed 

 by error, leaves not the shadow of a doubt upon our mind 

 of their prior existence in another condition. 



We should not omit to mention a very common mis- 

 take with respect to seeking after Infusoria. Some persons 

 imagine that if they procure a portion of fetid ditch water, 

 or take a few flowers and immerse them in a flower glass 

 full of water, they will be furnished in a few days with 

 all the varieties they may desire ; the fact, however, is 

 very diff'erent from this. It is true, that in such cases. 

 Infusoria will be found, but they will be only of the most 

 ordinary kinds. Those of high interest, either as regards 

 their structure, form, or colour, like all the other master- 

 works of Nature and of Nature's God, are not so easily 

 attained. Some degree of skill must be exercised for the 

 purpose. But as we shall fully explain this matter in the 

 section on the method of procuring and selecting In- 

 fusoria, we need not proceed further with the subject 

 here. 



