410 Proceedings 6f the Werneiri^ Society. 



lent opinion with granite veins, it was seen lo be in manj- cases unsnb 

 stantiated, and as a proof of tliis, instances were broughtfrom many granite 

 districts, where granite veins passed through each other, in some cases to 

 all appearance causing dislocations in these, while in others they did not; 

 whether or not, however, there was the least resemblance of a shift in 

 those veins, they nevertheless all occurred in perfectly unshifted strata 

 and laminae. Mr Cunningham remarked, however, that, although such a 

 phenomenon as that might render the shifted nature of granitic veins 

 very probable, the reverse appearance which he had often seen, viz. the 

 fact of unshifting veins in shifted strata and laminse, rendered it still 

 more probable that the whole of these indications of motion, whether in 

 the strata or in the granite, are of an entirely deceptive nature. In re- 

 gard to the relations of what are called contemporaneous veins of granite 

 to each other, it was said, that the very same phenomena presented them- 

 selves, and that such granite veins sometimes cross others and shift them, 

 but that all are so inclosed in granite, that in some instances when it is 

 large granular, crystals of felspar and mica were detected, which, although 

 separated by these veins, were still completely undisturbed. As in instances 

 that had before been explained, there was then a mass, to all appearance 

 shifted, enclosed in another evidently unshifted. Concerning the rela- 

 tions of granite concretions to each other, it was from many instances 

 shewn that these were of the same kind as the relations of granite veins 

 to each other, and to the strata they occur in. When, on this part of the 

 subject, the author brought forward in support of his opinions in regard 

 to granite, a case from Sutherlandshire, in which a large concretion tra- 

 versed strata and shifted another great concretion, and said that, what 

 was remarkable, a portion of the shifted concretion sent veins into what 

 in plutonic language was to be viewed as the shifting agent. Mr Cun- 

 ningham then proceeded to examine the more minute relations of one 

 crystal to another, and from this shewed that the appearances only dif- 

 fered from the relations of strata to granite on the great scale, and of 

 granite veins and concretions to strata in the circumstance, that the re- 

 lations of crystals to each other were on an almost microscopic scale. 

 The connections of granite being thus described, the author then pro- 

 ceeded to examine their resemblance to phenomena attending the va- 

 rious members of augitic or trap series, it was shewn that that group, 

 though it is most probably of an igneous origin, had still, through some un 

 known process, so connected itself with stratified masses, as to cross iheYt 

 horizontal beds without deranging them. Mr Cunningham, in proof of 

 tLe fact that even trap had sometimes not effected motions in rocks, or at 

 all events left no signs of it, described two instances in which he had 

 found fossil organic bodies to be crossed b^- veins without disturbing 

 them. One instance noticed was from the cliffs of Camustranivig in 

 Skje, where a large ammonite was traversed by a trap vein ; another was 

 from Mull, where several gryphea incurvsa were similarly crossed. In 



