360 Dr. Tony on Columbile. [Nov. 



spring not far from the house of Gov. Winthrop, near New 

 London. It has, however, been many years sought for without 

 success ; and some mineralogists have doubted whether the 

 specimen in the British Museum was found in Connecticut, or 

 in any part of this country ; but thai it was a Swedish specimen 

 of tantalite, which had by mistake been labelled as North 

 American. 



In a collection of minerals which I sent many years since to 

 Count Trolle Wachtmeister, this distinguished savant informed 

 me, that in one of the specimens from Haddam, containing 

 cymophane, beryl, &c. Prof. Berzelius had detected the tanta- 

 lite, and that it exactly resembled that of finbo, in Sweden. A 

 notice of this discovery I published in the fourth volume of Silli- 

 man's Journal, but it has been overlooked by Cleaveland in the 

 second edition of his excellent work, and also by Phillips, in the 

 last edition of his Mineralogy. As soon as I received this inte- 

 resting information, I carefully examined the one or two speci- 

 mens of the Haddam rock remaining in my possession ; but 

 without finding the substance which I supposed Berzelius 

 alluded to ; and since that time until lately, I had made no other 

 search for it. A few weeks since, however, in examining some 

 splendid specimens of the above-mentioned remarkable rock, 

 presented to me by Col. Gibbs, I observed, disseminated through 

 one of them, several small masses of a blackish substance, hav- 

 ing the appearance of an ore ofmangane.se. On a more atten- 

 tive examination, it presented some unusual characters, and at 

 length I discovered a considerable number of minute crystals, 

 which were evidently of the same mineral with the masses. It 

 occurred to me that this was the tantalite of Berzelius, and a 

 chemical examination of the small portion of the mineral which 

 I could sacrifice for this purpose, left little doubt on the subject. 

 The following is a more particular description of the mineral. 



It occurs in small amorphous masses, and in minute crystals, 

 disseminated in a granitic aggregate, consisting of quartz, 

 albite,* talc, friable manganesian garnet, beryl, cymophane, Sec. 

 The amorphous masses, which are probably very imperfect crys- 

 tals, are from one-fourth to half an inch in diameter, of a greyish 

 black colour, with the surface always more or less irised. It is 

 opaque. Its structure is imperfectly foliated. Its fracture is 

 somewhat conchoidal. It is not magnetic, either before or after 

 being heated by charcoal. It is sufficiently hard to scratch 

 glass, but not to strike fire with steel. The powder of the 

 mineral is very dark brown. Specific gravity 5"90. Before the 

 blowpipe, it is nearly infusible, the smallest fragment being 



• Cleavelandite of H. J. Brooke, Esq. as proposed in the last edition of Phillips's 

 Mineralogy. It is a subject of regret that this name must be given up for that of albite, 

 the latter having been several years since proposed by Hisinger and Berzelius for these 

 varieties of feldspar having a base of soda. 





