258 Dr. J. W. Webster on St. Michaei 
found to be much more porous and vesicular than any lava 
Ihad previously seen. The cells were nearly perfect 
with a smooth and hard crust. The partitions between the 
cells were less than the sixteenth of an inch in thickness, 
and had an imperfect glimmering lustre on the fresh frac- 
ture. Most of them contained a loose brown, earthy mat- 
ter, probably the result of partial decomposition. ‘The sta- 
actites, externally, have a dark iron grey colour, sometimes 
passing to black, and they are deeply channelled in a longi- 
tudinal direction. They occur of all sizes, some of them 
re less than an inch in length, while others exceed a foot. 
Their diameter is not less variable but never exceeds six 
inches at the thickest part. Those which were about a foot 
in length, were usually from one to three inches thick.” 
When these stalactites were broken, water fel] from them, 
but externally theyjweredry. The attraction of the volcanic 
rocks of this island for moisture is observed by the author to 
be very great and to this he attributes in a good degree, the 
fertility of these regions: the same remark holds true of 
other volcanic regions, and even of trap countries although 
in this respect they are less remarkable. 
“The difficulty of penetrating to the last apartment of the 
cavern, was by no means inconsiderable, and for the last 
few yards, we were obliged to creep upon the bottom, and 
advance with the utmost caution, while the sharp points 0 
hundreds of stalactites were in contact with our clothes.” 
Some of the circumstances noticed in the lava of these cav- 
erns, are curious, &. throwing light on the manner in whic 
they may have been formed, the’ lava appearing like melted 
lead thrown into water—the walls ‘‘ in some places seem t0 
be covered with petrifactions or vegetables, and shrubs, Te- 
taining the most perfect resemblance to their originals,” 
some specimens resembled bunches of grapes partially flat- 
tened, and some were like “ coarse lace.” ; 
- Chap. XII. “ of St. Michael continued—Erup- 
tions from the sea.” In addition to the facts which the author 
examined in person, as to the structure of the rocks, &c. he 
has given the details of the recent volcanic eruptions, all 
proving these islands to be “ among the most recent forma- 
tions of our globe,” but we have notroom for extracts from this 
