148 Geological Society. 



by the cross courses, and these laUcr at the place of inter- 

 section are found to be not only enlarged, but impregnated 

 •with ore. The contents of the cross courses are clay, 

 quartz, or a mixture of both. It was in one of these cross 

 courses, at the place of Its junction with one of these me- 

 talliferous veins, that the celebrated deposit of silver was 

 found mingled with galena, with iion pyrites, with bismuth, 

 cobalt, and woliram : aud these substances were also 

 found in those parts of the vein adjacent to the cross 

 course. 



Huel Alfred is in immediate contact with the niines just 

 inenlioned, and is, at present, one of the richest and most 

 profitable copper mines that Cornwall can boast of. The 

 great deposit of ore is contained in a contre from 9 to 24 

 ieet wide, which is considered as the continuation of that 

 in Herland mine. The conire traverses a regular east and 

 ^ve«t vein ; and it is remarkable that the ore, abundant as it 

 is, has hitherto been found only in one mass at the depth of 

 117 fathoms, at the point of junction of the contre and of 

 the vein, giving off a branch J 10 fathoms in length, along 

 the eastern part of the same vein. 



Another singular circumstance in this mine is, that one 

 of the cross courses is heaved and intersected by an E and 

 W vein. 



Since the beginning of 1801, there have been sold about 

 45,000 tons of copper ore, the produce of Huel Alfred, for 

 the sum of about 350,000/. of which the prolit divided 

 among the adventurers has amounted to about 120,000/. 



January 15lh. (The President in the chair.) A paper 

 by Wm. Conybeare, Esq. M. G. S, *' On the Origin of a 

 remarkable Class of Organic Impressions occurring in No« 

 dules of Flint," was read. 



This paper, which is chiefly occupied by detailed explana- 

 tions of the drawings bv which it is accompanied, relates iq 

 a class of substances thus chavactcrized by Mr. Parkinson, 

 in the second volume of his work on Organic Ren)ains : 



^* Small round compressed bodies not exceeding the 

 eighth of an inch in their longest diameter, and horizontally 

 disposed, are connected by processes nearly of the fineness 

 of a hair, which pass froni diflerent parts of each of these 

 bodies, and are attached to the surrounding ones ; the 

 whole of these bodies being thus held in connexion." p. 75. 



Mr. Parkinson conjectures that the formation of these 

 bodies has been the work of some polvpe, similar to those 

 by which the common zoophytes have been constructed, and 

 thcrtfore dashes ihejn among fossil corals of unknown 



crcncra. 



