LA GHACIOSA. 31 



families, the branches of some subterranean phxnts, and CiiAl'. il. 

 vegetables transported into mines in which the air colour 

 contains hydrogen oi' a great quantity of azote, become witiiout 

 green without light. From these facts one might be '^ ' ' 

 induced to think that the existence of carburet of iron, 

 which gives the green colour to the parenchyma of 

 plants, is not dependent upon the presence of the solar 

 rays only. Turner and many other botanists are of Marine 

 opinion that most of the seaweeds which we find floating "'--'' 

 on the ocean, and which in certain parts of tlie Atlantic 

 present the appearance of a vast inundated meadow 

 grow originally at the bottom of the sea, and are torn 

 off b}^ the waves. If this opinion be correct, the femily 

 of marine algs presents great difficulties to those jthy- 

 siologists who persist in thinking that, in all cases, the 

 absence of light must produce blanching. 



The captain, having mistaken a basaltic rock for a Opportune 

 castle, saluted it, and sent one of the officers to inquire ™'''"'^'^ 

 if the Englisli were cruising in those parts. Our 

 travellers took advantage of the boat to examine the 

 land, which they had regarded as a prolongation of the 

 coasts of Lancerota, but which turned out to be the 

 small island of La Graciosa. " Nothing," says Hum- 

 boldt, " can express the emotion a naturalist feels when Emotions on 

 for the first tune he lands in a place which is not ''^"''^"S 

 European. The attention is fixed upon so many ob- 

 jects, that one can hardly give an account of the impres- 

 sions which he receives. At every step he imagines 

 that he finds a new production ; and, in the midst of 

 this agitation, he often does not recognise those which 

 are most common in our botanical gardens and museums." 

 A fisherman, who, having been frightened by the firing, 

 had fled from them, but whom the sailors overtook, 

 stated that no vessels had been seen for several weeks. 

 The rocks of this small island were of basalt and marl, 

 destitute of trees or shrubs, in most places without a 

 trace of soil, and but scantily crusted with lichens. 



The basalts are not columnar, but arranged in strata 

 from 10 to IG inches thick, and incline to the north-west 



