566 



THE POPULAR SCIENCE MONTH LI 



:r 



tance of between six and eight hundred miles. 

 At these distances the bodies of the fish be- 

 come covered with bruises, in which patches 

 of white fungus are developed; their fins 

 become mutilated, their eyes are often de- 

 stroyed, parasitic worms gather in their gills, 

 they become emaciated, the flesh becomes 

 white from the loss of the oil, and they all die 

 as soon as the spawning act is accomplished, 

 often before. So far as has been observed, 

 they nre not known to feed after entering 

 the rivers. The spawning-season varies in 

 different rivers, and different parts of the 

 same river, but not in the different species, 

 and probably extends from July to December. 

 In the spring the fish are silvery, spotted or 

 not, according to the species, and have the 

 mouth about equally symmetrical in both 

 sexes. As the spawning-season approaches, 

 the female loses her silvery color, and be- 

 comes more slimy, the scales on the back 

 partly sink into the skin, and the flesh 

 changes from a salmon-red to a paler color. 

 As the season advances, the differences be- 

 tween the males and females become more 

 marked, in proportion as the milt is devel- 

 oped. The difference in the economic 

 value of the spring and fall salmon, which 

 is vastly in favor of the former, is depend- 

 ent on the fact that the spring salmon 

 enter the rivers long before the growth 

 of the organs of reproduction has reduced 

 the richness of the flesh, while the fall 

 salmon can not be taken in quantity until 

 their flesh has deteriorated. The quinnat 

 is more valuable, on account of its size and 

 abundance, than all the other fishes on the 

 Pacific coast together; and the blue-back is 

 worth much more than the combined value 

 of the three remaining species. " It is the 

 prevailing impression," say the authors of 

 the report, "that the salmon have some 

 special instinct which leads them to return 

 to spawn in the same spawning-grounds 

 where they were originally hatched. We 

 fail to find any evidence of this in the case 

 of the Pacific coast salmon, and we do not 

 believe it to be true. It seems more prob- 

 able that the young salmon, hatched in any 

 river, mostly remain in the ocean within a 

 radius of twenty, thirty, or forty miles of 

 its mouth. These, in their movements 

 about in the ocean, may come into contact 

 with the cold waters of their parent rivers, 



or perhaps of any other river, at a consider- 

 able distance from the shore. In the case 

 of the quinnat and the blue-back, their 

 " instinct " leads them to ascend these fresh 

 waters, and, in a majority of cases, these 

 waters will be those in which the fish in 

 question were originally spawned. Later 

 in the season the growth of the reproductive 

 organs leads them to approach the shore 

 and to search for fresh waters, and still 

 the chances are that they may find the orig- 

 inal stream. But undoubtedly many fall 

 salmon ascend or try to ascend streams in 

 which no salmon was ever hatched." The 

 evidence is not clear whether salmon are 

 diminishing in numbers or not, except in 

 the Sacramento River, where they are un- 

 doubtedly decreasing. 



Storage of Eleetricity. The reproach 

 against electricity that it can not be stored 

 seems now to be in a fair way of being re- 

 moved by M. Camille Faure's recent im- 

 provement of the Plante secondary battery. 

 The cells of this battery, as is well known, 

 consist simply of two lead plates immersed 

 in acidulated water, one of which becomes 

 oxidized by the passage of a current through 

 the cell, and is reconverted into the me- 

 tallic state when the charging current 

 ceases, yielding a current while undergoing 

 this latter transformation. Once charged, 

 the battery may be kept a considerable 

 length of time without losing its power, and 

 gives out a current steadily in a manner 

 similar to an ordinary voltaic cell. The 

 Plante cell is, however, not of commercial 

 value, as its capacity is small, and it requires 

 a considerable time to charge it. These 

 difficulties M. Faure appears to have largely 

 overcome by simply coating the plates with 

 minium or red-lead, whereby their chemical 

 dissimilarity, and consequently the electrical 

 capacity of the cell, is greatly increased. 

 When the charging takes place, the minium 

 upon one plate is further oxidized to the 

 peroxide, and that upon the other reduced 

 to the metallic state, a current being given 

 out while these plates are assuming their 

 original condition. The cell is stated to give 

 eighty per cent, of the current used to charge 

 it, and to retain its charge for a consider- 

 able period. A battery containing four cells, 

 and of the size of a cubic foot, was recent- 



