Professor Buckland's Instructions, 8fC, 249 



krly foliated and some specimens are translucent on 

 the edges, but it is to be remarked, that neither the crys- 

 talization or translucency are perfect, such as we see them 

 in well characterized specimens of primary limestone. A 

 faVther examination has also disclosed to me organic petri- 

 factions of madreporites, and other relics, very sparingly im- 

 bedded, and sometimes not to be noticed for miles in suc- 

 cession, even where the abrupt nature of the country ex- 

 poses it to examination. The metalliferous formation is 

 overlayed by a stratum of calcareous carbonate manifestly 

 secondary, but this appears to have been much broken 

 down, and washed away, as it is only seen capping bluffs 

 and eminences. 



As to the primitive region which I have described about 

 the sources of the river St. Francis, you can place every 

 reliance upon it. It will be necessary, however, carefully 

 to distinguish the limits which I have fixed to this forma- 

 tion, and which, I believe, are defined with sufficient pre- 

 cision in the work. The rock here is red granite, consist- 

 ing, mainly of feld spar and quartz, with very little mica. 

 It is traversed by veins of green stone, which is in some 

 places rendered porphyrytic by large greenish and flesh- 

 coloured crystals of feld spar. Of all these I shall take a 

 pleasure in furnishing you duplicate, on my arrival at New- 

 York, in the spring, as my specimens are now there, and I 

 shall have no means of access to them before that time. 



Art. IV. — ^Instructions for conducting Geological Inves' 

 tigations, and collecting Specimens ; by Rev. Professor 

 BucKLAND, of the University of Oxford, England. 



(Communicated for insertion in this Journal by Prof. Hare of Philadelphia.) 



In collecting specimens to illustrate the geology of our 

 country, one great object is to obtain those substances which 

 are of most common occurrence in it. 



* In Vol. I. (p. 71) of this Journal, we published the instructions of Mr. 

 Brongniart for collecting- geological specimens, especially those containing 

 organized remains. Wishing to give as wide a circulation as possible to 

 this species of information, so eminently needed in this country — we now 

 publish the instructions of Professor Buckland which, if we mistake not, 

 will be found like those of Mr. Brongniart, to be drawn up with that skill 

 which we might indeed expect from men so thoroughly versed in the subject. 



Vol, III No, 2. 32 



