SALMON. 



589 



The water in which they live is of course one of 

 the circumstances by which they are affected the 

 most, and the differences which affect them may be 

 the temperature of the water, the substances which 

 it holds in solution, or the food which it supplies. 

 Those which have seasonally free access to the sea, 

 have of course a more constant uniformity in the 

 state of their dwelling there than those which are 

 confined to the inland waters. But still there are 

 differences in the appearance of the salmon even of 

 rivers which flow into the sea at no great distance 

 from each other. Thus in the case of the rivers oft 

 Scotland, one might be perhaps prepared to find dif- 

 ferences in those of two great estuaries like the Forth 

 and the Tay, which are separated from each other by 

 a whole country. But this is not all ; for the fisher- 

 men can readily tell from which of the smaller salmon 

 rivers which fall into these estuaries, a fish comes. It is 

 a general law that the nearer to the open sea the mouth 

 of the river is, the fish are the finer both in colour 

 and in flavour ; and a Tay salmon caught below Dun- 

 dee is far better than one caught above Perth, and 

 in all rivers the farther inland the fish are obtain- 

 ed, they are always the worse in quality. This is 

 still not the only difference ; for the salmon of rivers 

 which have low and warm courses and clear water, 

 are always finer, as well] as found earlier, than those 

 in mountain ones, where the water is much tinged 

 with peat earth. Thus, on the Fife side of the firth 

 of Forth, a Leven salmon is better than one found at 

 the confluence of the mountain rivers farther up the 

 Forth. It appears to be the pure water much more 

 than the rich country through which the river flows, 

 which improves the character of the fish. So also, at 

 Aberdeen, the Dee and the Don enter the sea at no 

 great distance from each other, and the valley of the 

 Don is richer than that of the Dee ; while the Dee, 

 from the greater purity of its water, is by much the 

 better salmon river of the two. These facts are well 

 known to fishermen on the rivers and also to dealers. 

 Many more might be given, but these are sufficient 

 for proving the point. 



The alternate adaptation of those Salmonidce which 

 migrate between the sea and the river, to the salt 

 water of the one, and the fresh water of the other, 

 shows that they are readily obedient to circumstances. 

 It is doubtful whether upon an instant transfer from 

 the one to the other the animal would live, or at all 

 events be uninjured ; but some additional information 

 is wanted before this point can be cleared up in a 

 manner quite satisfactory. It is probable, however, 

 that they " hang" in the brackish water for some time, 

 both in their ascent and descent ; and the probability 

 of this is strengthened by the fact that they do not 

 ascend the smaller streams which enter the sea 

 abruptly, with little, brackish water at their union. 



Of the three species, the salmon, the bull-trout, and 

 the sea-trout, which have this migratory habit, the 

 salmon is certainly the most discursive, both seaward 

 and inland ; and, in Britain at least, it appears to be 

 more generally distributed, although the others are 

 very numerous at some places. The bull-trout is 

 perhaps the next in point of discursiveness, at least 

 up the rivers, though its inferiority for the table 

 makes it less an object of interest. It is a more hardy 

 fish than the salmon, and ascends the rivers earlier ; 

 but as it is in little demand at the great markets 

 where so much salmon is purchased, its history is left 

 more to naturalists, and its flesh to the country people 



where it is found. The sea-trout, or the salmon- 

 trout, as it is more correctly called, resembles the 

 salmon more in appearance, and also in the quality of 

 its flesh, than the bull-trout does ; but it is the least 

 discursive up the rivers of the whole, and probably 

 does not go so far to sea, or into such deep water as 

 the salmon. It is often found in shoals of consider- 

 able number beating about the coasts, and even in 

 the mouths of the smaller rivers, which the salmon do 

 not enter. But it does not ascend very far up these 

 rivers, even where there is little or nothing to stop its 

 progress ; and thus it may be considered as more a fish 

 of the shores and the brackish waters, than of any other 

 locality. On these accounts it would appear to be 

 less affected by seasons than the salmon. It is, how- 

 ever, a good deal affected by the character of the 

 waters, being always in the best condition where the 

 water is pure, and the soil from which it comes, espe- 

 cially on the lower part of the river, rich. On the shores 

 of the Hebrides, especially in the sandy bays, which 

 are generally found skirting the more fertile spots, 

 the salmon trout is found in great abundance and of 

 excellent quality, even where there are no streams of 

 any consequence. In many of these places it attains 

 considerable size, is in fine flesh both as to colour 

 and quality, and called salmon by the inhabitants. 



But the changes which are produced by differences 

 of quality or admixture in the water, even in those 

 species which never resort to the sea, are fully as con- 

 spicuous as those which the fresh and the salt water, 

 and the different qualities of the latter in the several 

 rivers, occasion. We might be prepared to expect 

 this; because the quality of the water of a river 

 where it falls into the sea is different from that of the 

 inland branches of the very same river. The ultimate 

 river, as we may call it, is a mixture of many minor 

 waters, each partaking of the characters of the par- 

 ticular soil from which it comes. One may be from 

 the mountain, a second from the moor, a third from 

 the morass, a fourth from the grassy valley, and so oh 

 through a very great number; and the compound 

 will partake of the nature of all of them, in the pro- 

 portion in which they happen to enter into it. Then 

 after these are all collected into the main channel, 

 the impurities may subside there, and give very dif- 

 ferent characters to different parts of the river. All 

 these have very decided effects upon the Salmonidce, 

 especially upon such as are permanently resident, in 

 the appearance and colour, and also in the quality, of 

 the flesh. If from any accident the waters become 

 permanently foul, the Salmonidce quit them sooner than 

 any other iishes, and the salmon is the first to depart, 

 or rather it ceases to resort to those polluted waters. 

 The impurities of all kinds which mix with the Thames 

 may be said to have completely banished the salmon 

 for which that river was so celebrated in former times, 

 and there are many other instances. A remarkable 

 one occurred in the Ness, between Inverness and 

 the lake where the operations on the Caledonian 

 Canal rendered it necessary to turn the river into a 

 partially new channel. In doing this, great part of 

 the old channel was filled with loose gravel and sand, 

 tinged more or less with iron, of which the curious 

 little hills in the lower valley of the Ness are com- 

 posed. This banished the salmon ; and when they 

 are once banished from any locality, they do not soon 

 return, even though the cause which banished them 

 should cease to operate. We might be prepared to 

 expect this, from the fact that the salmon resort so 



