SELF-PURIFYING QUALITY. 433 



the water. After a volcanic eruption in Iceland, 

 the fish all deserted the sea coast, thus evidently 

 showing that something had been added to the 

 water unfavourable to their existence. It was one 

 of the plagues visited upon the obduracy of the 

 Egyptian monarch, that the fish that were in the 

 river died, the waters having become poisonous 

 to them by the remarkable change mentioned 

 in the Scriptures. Beyond these facts, which 

 have only a local bearing, ocean-chemistry is 

 not empowered to speak. It is possible there 

 may be a state of poisonous diffusion in the 

 waters analogous to our malaria, or even to our 

 epidemics ; * but we can scarcely be said to be in 

 possession of a single fact to justify this conclu- 

 sion. Doubtless, the inhabitants of the deep 

 are not exempt from disease and death ; but no 

 evidence exists to favour the supposition that 

 the regions of the deep are desolated as those of 

 the dry land by the infliction of epidemics. 



There can be no question that a self-purify- 

 ing property has been given to the ocean, little 

 though its phenomena are as yet understood. 

 Dr. Smith, in the Researches in the Air and 

 Water of Towns, before quoted, has particu- 



* It must not be considered that the brute creation arc 

 exempt from epidemics. Every agriculturist can add his tes- 

 timony to the fact, that epidemic disorders, frequently of a 

 most alarming character, appear among the lower animals. 



2 F 



