IGNIGENOUS ROCKS. 47 



commencement of the first day of creation. Some, poisoned 

 by infidelity, and voluntarily blinded to a sense of the un- 

 philosophical nature of arguments which they considered 

 conclusive, have, that they might not see in this science in- 

 dubitable proofs of Deity, held it up to scorn ; but we are 

 not aware that any have enlisted under the banners of 

 scepticism from finding that, after properly studying Na- 

 ture, it appeared at variance with Revelation, or that " He 

 who made the world, and revealed its date to Moses, was 

 mistaken of its age.''' 



Before entering into a minute detail of the various 

 changes exhibited in different localities, which the stratified 

 rocks have undergone, by being in connexion with the un- 

 stratified, we shall notice the characters which rocks of both 

 classes when in contact are found to exhibit in a greater or 

 less degree. When in contact with Neptunian formations, 

 all the unstratified rocks of the Lothians exhibit more 

 or less a change of structure. If the rock is granular, 

 when at a distance from the stratified ; when in contact with 

 it, it is found small granular or compact, and apparently 

 homogeneous throughout. If, when at a distance from the 

 stratified rock, the unstratified rock is compact, as it ap- 

 proaches the former it becomes still more dense. Greenstone 

 passes into basalt, and compact felspar into one still more 

 compact. It is probable that the causes of all these changes 

 are to be found in differences in the rate of cooling, a cause 

 which, no doubt, has been productive of much of that end- 

 less variety which is observable in the Trap series. That 

 the planes of contact of the igneous rock with that of Nep- 

 tunian origin were the very places where such changes would 

 be produced, is to be supposed, if we recollect that, before 

 the appearance of these igneous rocks, they had been un- 

 disturbed, and all undergoing from various actions a pro- 



