174 



CHAP. XXIX. 



Quartz Rock. Red primary Sandstone. 



As Quartz rock has been either entirely overlooked 

 or misapprehended by all systematical writers, and, 

 until I had described it, by all observers, it is probably 

 rare in Europe. It would be unbecoming to suppose 

 such oversights and errors, had it occurred, as it does 

 in our own island, in countries so often examined by 

 geologists of reputation : though others must explain 

 the cause of its fate here, as, in so doing, they may 

 learn to estimate more correctly, the teachers and 

 writers in whom they have trusted. Its history is 

 therefore drawn solely from my own observations in 

 Scotland ; the materials having been originally pub- 

 lished in the Geological Transactions: while I may 

 now name the few instances in which it has been no- 

 ticed elsewhere, since it thus received a leading place 

 in the system of rocks. Von Buch describes it in 

 Norway, and Brongniart in La Mancha ; the fictitious 

 Ali Bey mentions it as abundant near Mecca ; and it 

 occurs near Lima and in Brazil, in tracts equalling 

 that of Jura : though if Hurnboldt was unable to de- 

 termine its stratification or explain its nature, we must 

 remember that it had not then been noticed in any 

 geological writings. Future observers, now informed 

 of its nature as well as its existence, will probably find 

 this important rock much more frequent than it was 

 suspected to be while yet undescribed. We are 

 taught, even to see. 



Quartz rock, like limestone and argillaceous schist, 

 has its counterpart in the secondary sandstones, but is 

 not exclusively formed of the mineral whence it derives 

 its name. The more important varieties may, how- 



