Prof. Hitchcock on Fossil Footmarks, Lincolnite, ^. 65 



the crystals which I have examined, stand out distinct and 

 alone ; and are most obviously, a right oblique angled prism, un- 

 modified. 



I have recently received a letter from Mr. Teschemacher, from 

 which it appears doubtful whether he has ever measured any 

 crystals of Lincolnite. He says, "Without intending to cast 

 even the imputation of error on Mr. Alger's statement, I must say, 

 that of my own knowledge, I never measured Lincolnite. Mr. 

 Alger sent me a small parcel of crystals of Beaumontite, for 

 measurement, with a view of ascertaining their identity with 

 Heulandite ; several of which I measured and found the angles 

 agree. Among them was a single crystal, wrapped in paper, 

 which I believe I also measured. Mr. Alger says now, that this 

 was a crystal of Lincolnite. He at various times made inquiries 

 of me, respecting my opinions of the identity of both Lincolnite 

 and Beaumontite with Heulandite, which I freely gave him, and 

 entered into various particulars on the subject ; but he never 

 gave me the slightest reason to imagine that he was writing a pa- 

 per on the subject, for publication, in which these would be em- 

 bodied and my name used, or I should have been more cautious. 

 You must be well aware, that under these circumstances, I can- 

 not allow my name to be used as deciding the point in ques- 

 tion, without further investigation. And I think it right, there- 

 fore, to put you in possession of the facts. 



"I might, and believe truly that I did, measure the crystal; 

 but I know that I measured several, from which, owing to the 

 small size of the modifying planes, the peculiarity of .the light, 

 &c., I could draw no satisfactory conclusion; and which I put 

 away, selecting others which could be more easily measured. 

 This single crystal was probably one of these ; for supposing it 

 Beaumontite, I did not pay the attention to it 1 should have done, 

 had it been sent to me as Lincolnite." 



In view of the above facts, you will pardon me for believing, 

 that the claims of Lincolnite to be regarded as a distinct species, 

 have not yet been set aside. But as I am almost entirely desti- 

 tute of specimens, I fear that little farther progress will be made 

 on the subject, unless some one has more time and zeal than I 

 have, to explore the localities anew. 



Amherst College, Oct. 2oth, 1844. 



Vol. xLviii, No. 1.— Oct.-Dec. 1844. 9 



