164 FEAGMENTS OF SCIENCE. 



thus taken up, as well as the remaining half, being 

 precipitated. The solid precipitate is permitted to 

 sink, and the clear supernatant liquid is limpid soft 

 water. 



We returned to the real mouth of St. Michael's 

 Cave, which is entered by a wicket. The floor was 

 somewhat muddy, and the roof and walls were wet. We 

 soon found ourselves in the midst of a natural temple, 

 where tall columns sprang complete from floor to roof, 

 while incipient columns were growing to meet each other, 

 upwards and downwards. The water which trickles 

 from the stalactite, after having in part yielded up its 

 carbonate of lime, falls upon the floor vertically under- 

 neath, and there builds the stalagmite. Consequently, 

 the pillars grow from above and below simultaneously, 

 along the same vertical. It is easy to distinguish the 

 stalagmitic from the stalactitic portion of the pillars. 

 The former is always divided into short segments by 

 protuberant rings, as if deposited periodically, while 

 the latter presents a uniform surface. In some cases 

 the points of inverted cones of stalactite rested on the 

 centres of pillars of stalagmite. The process of solidi- 

 fication and the consequent architecture were alike 

 beautiful. 



We followed our guide through various branches and 

 arms of the cave, climbed and descended steps, halted 

 at the edges of dark shafts and apertures, and squeezed 

 ourselves through narrow passages. From time to time 

 we halted, while Mr. Crookes illuminated with ignited 

 magnesium wire, the roof, columns, dependent spears, 

 and graceful drapery of the stalactites. Once, coming 

 to a magnificent cluster of icicle-like spears, we helped 

 ourselves to specimens. There was some difficulty in 

 detaching the more delicate ones, their fragility was so 

 great. A consciousness of vandalism, which smote me 



