43 



copper, of which several run nearly in a parallel direction from east 

 to west. 



The peculiarity here is, that there are several cross courses which 

 run north and south, the greatest part of which contain no metal : 

 these meeting with the lodes of copper ore, interrupt their continuity, 

 or, as is expressed by the miners, heave them out of their direction, 

 so that at the place of intersection the copper lodes seem to have 

 been forced aside eighteen or twenty inches. One of these cross 

 courses has of late been discovered to yield silver in no inconsider- 

 able quantity; but with this particular circumstance, that at and near 

 the place of intersection the ores both of silver and copper are much 

 less productive than at some distance from it. The silver ore con- 

 sists of a mixture of galena, native bismuth, gray cobalt, vitreous 

 silver, and native silver chiefly in a capillary form. 



Account of an Elephant's Tusk, in which the Iron Head of a Spear was 

 found imbedded. By Mr. Charles Combe, of Exeter College, Oxford. 

 In a Letter to the Right Hon. Sir Joseph Banks, Bart. K.B. 

 P.R.S. Read February 19, 1801. [Phil. Trans. 1801,;?. 165.] 



This tusk, which weighed fifty pounds, and measured about six feet 

 in length, is supposed to have been imported from Africa, and was 

 purchased at Liverpool by a manufacturer of Birmingham. On 

 shaking it, a rattling noise was heard near the middle part, which, 

 on cutting the tooth transversely, was found to be occasioned by an 

 iron spear-head, about six inches and a half long, which lay in the 

 longitudinal direction of the tooth, with the point foremost, and was 

 considerably corroded. It is conjectured that the spear had entered 

 at the basis of the trunk, between the interior angle of the eye and 

 the proboscis, the cavity of the tusk being placed immediately be- 

 neath this part. From the quantity of bony matter that had been 

 formed round this extraneous body, it is inferred that the animal 

 must have lived a considerable time after it had received the wound. 

 The spear-head and the part of the tooth in which it had been im- 

 bedded were exhibited to the Society at the close of the Meeting. 



Description of the Arseniates of Copper, and of Iron, from the County 

 of Cornwall. By the Count de Bournon. Communicated by the 

 Right Hon. Sir Joseph Banks,.Br*. K.B. P.R.S. ReadFebruary 1 9, 

 1801. [Phil. Trans. 1801, p. 169.] 



In the mine called Huel Garland, in the parish of Gwennap in 

 Cornwall, has lately been discovered a species of ore, consisting of 

 different combinations of the arsenic acid with copper and iron, 

 which, though some mention have been made of it by German 

 writers as having been found in Silesia, appears yet, from the great 

 abundance afforded by the above-mentioned mine, to be almost pe- 

 culiar to this country. After an historical account of the little that 

 has hitherto been known concerning this substance, Count Bournon 



