Wernerian Natural History Society. 3 87 



its turn,, is covered with basalt : the basalt gradually passes 

 into, and is covered with, porphyry-slate : and the porphyry- 

 slate, in some instances, appears to pass into greenstone, 

 which forms the uppermost portion of the formation : — So 

 that we have thus a beautiful series of transitions from the 

 coarse mechanical, to fine chemical ; that is, from trap-tuff 

 to porphyry-slate inclining to greenstone. The doctor also 

 remarked, that the amygdaloid contains crystals of felspar 

 which have an earthy aspect; the basalt, crystals of felspar 

 possessing the characters of common felspar; and the por- 

 phyry-slate, glassy felspar ;— r-facts which coincide with, and 

 are illustrative of the increasing fineness of the solution, from 

 the oldest to the newest members of the formation. - In the 

 course of his paper, the doctor gave distinct and satisfac- 

 tory answers to the following queries, which had been pro- 

 posed by professor Jameson : — 1, Does the Bass rock in the 

 Frith of Forth belong to the newest floetz-trap formation? 

 2. Does the sienitic greenstone of Fassnet in East Lothian 

 belong to the transition rocks, or to the newest floetz-trap 

 formation ? 3. Are the geognostic relations of the porphyry- 

 slate, or clinkstone-porphyry, of East Lothian, the same 

 as in other countries? The doctor announced his intention of 

 reading, at the next meeting of the society, a description 

 of the different veins that occur in East Lothian, and of 

 giving a short statement of the geognostical and ceconomi- 

 cal inferences to be deduced from the appearances which he 

 has investigated with so rmicb care. It is indeed only by 

 investigations like those of Dr. Ogilby, that we obtain anv 

 certainty respecting the mineral treasures of a country ; and 

 • such alone can afford us data for a legitimate theory of the 

 formation of the globe. 



At the same meeting, a communication from colonel 

 Montagu was read, describing a new species of Fasciola, 

 of a red colour, and about an inch long, which sometimes 

 lodges in the trachea of chickens, and which the colonel 

 found to be the occasion of the distemper called the gapes t 

 so fatal to these useful tenants of. the poultry-yard. The 

 knowledge of the true cause of this malady will, it is hoped, 

 soon be followed by the discovery of a specific cure: in the 



mean 



