316 Scientific Intelligence. {Arrit, 
Lustre, dull. Fracture, fine grained, even. Fragments irre- 
gular. 
It is probably composed of grains; but they are so small as 
scarcely to be distinguished by the naked eye. Opake. 
Soft, or at least easily scratched with a knife; but scarcely re- 
ducible to powder between the fingers. Under the pestle of an 
agate mortar it is easily crushed to the finest powder; so that the 
grains of which it is composed are exceedingly small. 
Specific gravity 1°6825. 
The remarkable property by which this stone is distinguished is, 
that when steeped in water it becomes exceedingly flexible in every 
direction ; but without the least elasticity. When allowed to dry it 
loses in a great measure this flexibility. Thus it differs from the 
flexible sand-stone ot South America, both in its external properties, 
and in the effect of water upon it. . 
To ascertain the constituents of this stone I fused 20 grains of it, 
previously exposed to a red heat, with carbonate of soda. The 
‘fusion was complete, and very easily accomplished, showing that 
the stone consisted chiefly of silica. The fused mass was dissolved 
in water, supersaturated with muriatic acid, and evaporated to dry- 
ness. The dry mass being washed in water, and thrown upon the 
filtre, left the silica. The liquid was precipitated by carbonate of 
soda, and the precipitate boiled in pure potash. Part was dissolved. 
The remainder was grey, dissolved with effervescence in muriatic 
acid, and formed selenite with sulphuric acid; it was therefore 
carbonate of lime, mixed with a very little iron. The selenite 
‘weighed 14 grain, indicating 0°62 grain of lime. The portion 
dissolved by the potash was alumina, and being thrown down 
by sal ammoniac, and washed and dried, it weighed 0°3 grain. 
Hence the stone was composed of 
SOUGE oict ant Nupebin icon a ei peloborwi’ay ws évtei os biattaceieine” Oem 
Lime with a trace of iron............ O°62 
ALOIS °s iecscde sip Ab oi ad cart ete he 
20 
II. Curiows Growth of a Plane Tree. 
Among the ruins of the old monastery of the New Abbey, in. 
Galloway, there is a plane-tree, about 20 feet high, which grows 
on the top of a wall built with stone and lime, Being straitened 
for nourishment in this situation, many years ago it shot forth roots 
into the open air. These neither died nor drew back, but de- 
scended by the side of the wall, which is 10 feet high. It was 
several years before they reached the ground, during which time 
they conveyed no nutriment to the tree, but were supported by it. 
At length they dipped into the earth, and have since enabled the 
tree to grow with vigour. Between the top of the wall and the 
surface of the earth they have never thrown out either branches or 
8 
