176 



became spar. The author exhibited analogous examples of fractures 

 and separations in the Beryl and Tourmaline. 



The author next adverted to the opinion, that the Calton was a 

 mass of trap which had burst through the coal formation ; and that 

 the anthracite was the altered bitumen, which the rising trap had 

 enveloped in its passage. But, in opposition to these views, although 

 countenanced by Jameson, Cunningham, and Milne, he stated that 

 the Calton, with the exception of its two small trap dykes, consisted 

 of a series of sedimentary matters or strata, which had been assorted 

 by water ; and that, in position, these strata occupied a place far 

 below the mountain limestone, as is demonstrated by their dip and 

 connection with the group extending under the coal measures from 

 the Castle Hill to Joppa, which he had no hesitation in referring to 

 the old red sandstone. 



3. On some Phenomena of Capillary Attraction observed with 

 Chloroform, Bisulphuret of Carbon, and other Liquids. 

 By Dr George Wilson. 

 The object of this couimunication was to bring before the Society 

 some phenomena which are exhibited when certain liquids, denser 

 than water, are exposed, while contained in glass or porcelain vessels, 

 to the alternate action of acids and alkalies. The liquids with which 

 the phenomena described were noticed, were chloroform, bisulphuret 

 of carbon, Dutch liquid (C* H* C1-), bromine, oil of cloves, of 

 sassafras, of cinnamon, and of bitter almonds. The majority of the 

 experiments were made with chloroform, and the phenomena pre- 

 sented in common by all the liquids mentioned were described in 

 full, as presented by chloroform. 



When that fluid is dropped into water, contained in a glass or 

 glazed porcelain vessel, it falls to the bottom as a brilliant, highly 

 mobile globule. If potass, soda, or ammonia, be now added, the 

 globule at once collapses, sinks as if pressed down by the alkali, and 

 flattens out on the bottom of the containing vessel. On slightly 

 supersaturating the alkali with an acid, the flattened chloroform 

 recovers, with great rapidity, its globular shape, as if suddenly 

 relieved from pressure. 



When the acid in its turn is supersatui'ated with alkali, the 

 flattening again occurs ; and by alternating the addition of these 

 re-agents, the same globule may be successively flattened and rounded 

 for any number of times. 



