53 



slight degree, impregnated with deleterious substances. 

 This is the reason why the Thames is deserted ; and, for 

 the same reason, other rivers also will be deserted in their 

 turn. 



It is a familiar fact, that lime is extremely noxious to 

 the Salmon. If lime be put into a stream or pool, the 

 Salmon very soon die ; and knowing this, the peasantry 

 frequently dam-up the small rivers, and put lime into the 

 pools, for the purpose of obtaining the fish. The very im- 

 provement of lands, therefore, by the use of lime, has, in 

 a greater or less degree, the effect of injuring the waters 

 in rivers. But how much greater must be the effect aris- 

 ing from the ingredients used in chemical bleaching, in 

 dye-works and such establishments, from the refuse of 

 gas-works, and from the many other noxious substances 

 which, in modern times, find their way into the rivers ? 

 What, even, must be the effect arising from the increase 

 of navigation, and from the copper on the bottoms of the 

 vessels ? Consider the state of the water in the wet-docks 

 in any of the great ports, the West India docks on the 

 Thames, for example ; and, consider what must, for a 

 time, be the state of any river into which the contents of 

 these docks are discharged ! 



If all these things, then, be put together, there can be no 

 difficulty in accounting for the falling-off of the Salmon 

 Fishery in such rivers as the Thames, the Clyde, &c. 

 Every where, more or less, these causes now exist ; though 

 they must more especially, be found in operation, in those 

 rivers which run through the seat of improvement, and of 

 trade and manufactures. Accordingly, we find that the 

 river fisheries have been injured exactly as improvement 

 has advanced, and trade and manufacture* have increased. 



