416 , Miscellanies. 



MISCELLANIES. 



DOMESTIC AND FOREIGN. 



1. Extract of a letter from Prof. Hitchcock, respecting the Lincoln- 

 iie. — I wish to say a few words in arrest of judgment respecting the Lin- 

 colnite, which Mr. Alger has endeavored to show, in Vol. xlvi, p. 235, 

 of this Journal, to be identical with Heulandite. His paper is also 

 published in the last No. of the Boston Journal of Natural History. 



This mineral was found by me, only in small quantity, more than thirty 

 years ago; and I had revisited the spot only once in that interval. I then 

 procured, within a few rods of the spot, some very minute crystals, which 

 I judged by the eye, to be Lincolnite ; and I found a like mineral on gneiss 

 at Bellows' Falls. But I never attempted to measure these minute crys- 

 tals. Those which I first obtained were much larger. Yet when Mr. 

 Alger requested specimens, I found that I had lost or parted with nearly 

 every one, except these small ones ; and I believe that these were the 

 variety placed in the State collection. Now it was probably these which 

 were measured by Messrs Teschemacher and Alger, and they may very 

 probably have been Heulandite. But I still feel quite confident that the 

 original crystals which I measured, differed from Heulandite by about 10°. 

 After reading Mr. Alger's remarks, I searched among my duplicates, and 

 found two isolated crystals of those first obtained; and on measuring 

 them, by marking their angles on a smooth hard surface, I found them to 

 be nearly 60° and 120°, as stated in my Report. More recently I have 

 discovered a still better specimen in the cabinet of Amherst College; and 

 at my request, Professor Shepard has applied the reflecting goniometer to 

 some of the crystals, and finds the angles of the base to be from 1 16° 45' 

 to 117° 15', as taken by the reflection of a strong lamp-light. 



I have never felt, or expressed, any great confidence that this species 

 would maintain its ground ; but it strikes me that as yet it has not been 

 identified with any other species. E. H. 



The primary lateral angle of Heulandite (M : T) equals 130° 30', and 

 differs widely, as Mr. Hitchcock states, from the angle obtained by Prof. 

 Shepard for Lincolnite. But the secondary prism formed 

 by the planes T and e, has for the lateral angle 115° 10', N. p /\ 



to which Prof Shepard's angles are as close, as could be I.-ti -f'-M 



expected from the mode of measurement. By lettering ^ — ■ — ' 

 the second of Prof Hitchcock's figures, (Rep. Geol. Mass. p. 663,) as an- 

 nexed, the relation to Heulandite is apparent. The plane e is that let- 

 tered / in most mineralogical works, and the figure is turned around, so 

 that this plane is brought in front. — Eds. 



