280 



sides by mountains from 800 to 2000 feet in height. At the north 

 or lower end, where it opens into Glen Eck, there is a series of 

 mounds of clay and gravel, crossing the valley like embankments, 

 and spread over a space of about 1800 feet in length, and from 350 to 

 600 in breadth. They are from 20 to 100 feet in depth. These 

 mounds have turned the river Sluan from its direct course down the 

 middle of the valley, and forced it to cut a passage towards the east 

 side. They consist of piles of incoherent clay and gravel, mixed with 

 blocks, all derived from the rock (mica slate) which bounds the valley. 

 In form, materials, and position, they exactly resemble the terminal 

 moraines found at the foot of valleys occupied by glaciers; and if 

 found in a similar situation in the Alps, would be at once recognised 

 as terminal moraines. 



The other moraines are in Glenmessan, about 10 miles southward 

 from Glensluan. They consist, first, of two mounds of clay and 

 gravel, mingled with blocks, stretching across the foot of Glenmessan 

 like embankments, and of the height of 40 and 77 feet respectively ; 

 secondly, of four other detached mounds, from 25 to 30 feet in 

 height, scattered over a small plain or meadow, half a mile farther 

 south. In the valley of Glenmessan, grooved rocks, and other marks 

 of glacial action, are also found, and strengthen the conclusion, that 

 a glacier once occupied the valley, and produced the mounds of clay 

 and gravel. 



Monday, 5th February 1855. 



The Right Rev. Bishop TERROT in the Chair. 



The following communications were read : — 



1 . On the Properties of the Ordeal Bean of Old Calabar, 

 Western Africa. By Dr Christison. 



In various parts of Western Africa it appears to be the practice 

 to subject to the ordeal by poison persons who come under suspicion 

 of having committed heinous crimes. On the banks of the Gambia 

 river the poison used for the purpose is the bark of a leguminous tree, 

 the Fillcea suaveolens of MM. Guillemin and Perottet. In the neigh- 

 bourhood of Sierra Leone it is the bark of Erythrophleum guineense, 



