434 THE CHEMISTRY OF CREATION. 



larly adverted to the self-purification taking 

 place in fresh-water. The organic matter is 

 precipitated as it is in fresh-water when it- 

 comes into contact with clay at the bottom of 

 the sea or with the mud on its shore. It is thus 

 rendered insoluble and innoxious. Another 

 portion of it, which remains in solution, be- 

 comes acted on by the various living creatures 

 peopling the waters ; and what escapes both 

 these processes is no doubt decomposed in the 

 manner already alluded to by the influence of 

 the air and ozone. In consequence of the 

 continued deposit which is taking place over 

 a great part of the ocean bed, the products of 

 these decompositions, when insoluble, are buried 

 at the bottom, and soon so entirely covered 

 over with a layer of detritus, as effectually to 

 protect the overlying waters from their influ- 

 ence. This purifying process is largely assisted 

 by the mechanical action of the waves. The 

 occasional ingredients locally present in the 

 waters of certain coasts, are removed by the 

 ordinary effect of chemical decomposition. 



Would that, as the result of the intelligent 

 and careful investigations of chemical philoso- 

 phers, we were in possession of more and better- 

 defined information on the chemistry of the 

 ocean than this chapter now contains ! 



