16 PAPERS, ETC. 
similar arragonite formed upon limestone. There is a wide 
difference between the rapidity of the growth ofthe arra- 
gonite and that of the common carbonate of lime, the latter 
increasing several inches in length, whilst the former makes 
an almost, or quite, imperceptible progress. Thirty five 
years ago I observed a small basin in the floor of the 
prineipal northern fissure of the cavern. This basin was 
then about fourteen inches in diameter and five inches in 
depth, and was kept full and overflowing by water con- 
stantly dropping from the stalactitie roof. The bottom 
and sides of the basin were formed of stalagmitic carbonate 
of lime. At present, instead of exhibiting a concavity 
five inches in depth, it presents the appearance of a’stalag- 
mitic convexity, having its centre elevated upwards of two 
inches above its eircumference, so that, measuring from the 
bottom of the basin, as it was thirty five years ago, and unto 
the top of its highest projection, as it is at present, it has 
grown fully seven inches in height, giving a stalagmitie in- 
crease of one inch every five years, or one-fifth of one inch in 
each year. Now this is certainly a mostrapid growth, and 
far greater than I should have anticipated. If loose stones 
are thrown into the water of the small pool at the western 
end of the main fissure, they are, after no long period, 
entirely covered with cerystallized carbonate of lime, in 
the well-known form of dogtooth spar. I cannot say how 
long a period is sufficient for this. This water holds a 
certain quantity of carbonate of lime in solution, with a 
little sulphate and muriate of lime, and a trace of common 
salt ; but I suspect that these ingredients vary in propor- 
tion at different times of the year. The arragonite found 
upon the roof of the cavern contains no strontia, which 
was at one time considered to be a necessary ingredient 
in all arragonites; but this is by no means the case, as, 
