A CURIOUS MISTAKE. 
34 
in short, vegetables transported into mines, where the am- 
bient air contains hydrogen or a great quantity of azote, 
become green without light. From these facts we are in- 
clined to admit that it is not exclusively by the influence of 
the solar rays that this carburet of hydrogen is formed in 
the organs of plants, the presence of which makes the 
parenchyma appear of a lighter or darker green, according 
as'the carbon predominates in the mixture. 
Mr. Turner, who has so well made known the family of 
the seaweeds, as well as many other celebrated botanists, arc 
of opinion that most of the f'uci which we gather on the 
surface of the ocean, and which, from the 23rd to the 35tli 
degree of latitude and 32nd of longitude, appear to the 
mariner like a vast inundated meadow, grow primitively at 
the bottom of the ocean, and float only in their ripened 
state, when torn up by the motion of the waves. If this 
opinion be well founded, we must agree that the family of 
seaweeds offers formidable difficulties to naturalists, who per- 
sist in thinking that absence of light always produces white- 
ness ; for how can we admit that so many species of ulvaceie 
and dictyote®, with stems and green leaves, which float on the 
ocean, have vegetated on rocks near the surface of the water ? 
From some notions which the captain of the Pizarro had 
collected in an old Portuguese itinerary, he thought him- 
self opposite to a small fort, situated north of Teguisa, the 
capital of the ' island of Lancerota. Mistaking a rock of 
basalt for a castle, ho saluted it by hoisting the Spanish flag, 
and sent a boat with an officer to inquire of the commandant 
whether any English vessels were cruizing in the roads. We 
were not a little surprised to learn that the land which we 
had considered as a prolongation of the coast of Lancerota, 
was the small island of Graciosa, and that for several leagues 
there was not an inhabited place. We took advantage of 
the boat to' survey the land, which enclosed a large bay. 
The small part of the island of Graciosa which we traversed, 
resembles those promontories of lava seen near Naples, 
between Portici and Torre del Greco. The rocks are naked, 
with no marks of vegetation, and scarcely any of vegetable 
soil. A few crustaccons lichen-like variolarise, leprarise, and 
urceo.arise, were scattered about upon the basalts. The lavas 
which are not covered with volcanic ashes remain for ages 
