THE SPANG COLLECTION OF MINERALS. 445 



now about to speak, the Columbite, on account of the derivation of 

 its name and the history of its discovery. The rare metallic element 

 columbium, or niobium as it has subsequently been called, was first 

 discovered in 1802, by Hatchett, in a specimen of this mineral sent 

 out by Governor Winthrop, of Connecticut, to Sir Hans Sloane, then 

 president of the Royal Society, and the original analysis was made 

 by Wollaston, with an accuracy truly surprising, upon only four grains 

 of the specimen, so long ago as the year 1809. It is highly probable 

 that Governor Winthrop's mineral came from Middletown, Connecti- 

 cut, at which locality some very large crystals have since been found ; 

 among many such in the Spang collection, there is one composed ot 

 twenty-five crystals compounded together, and showing the terminal 

 planes at the summit of each crystal. Two of the prismatic faces of 

 one of these crystals are three inches in length. 



There is a genus of minerals termed zeolites, from a Greek word 

 signifying to boil, for the reason that when heated the large percent- 

 age of water which they contain escapes with intumescence, and ot 

 these one of the most remarkable species is scolecite, so called because, 

 on touching it with the tip of a blow-pipe flame, it curls up like a 

 worm. I find elsewhere the record of some crystals, which were 

 found in the Berufiord, Iceland ; and which exceeded two inches in 

 length and were a quarter of an inch thick. There is a radiated mass 

 of scolecite crystals in this collection, brought from Poonah, Hin- 

 dostan, the largest being three inches in length, and compounded of 

 two twins, each of which is one-quarter of an inch in diameter. The 

 beauty of this group is still further enhanced by clusters of transpar- 

 ent tabular apophyllites attached to the sides of the crystals. 



There is another species of zeolite, which, on account of its brill- 

 iant, pearly lustre, has received the name of stilbite. Usually its 

 color is white ; in this collection there is a specimen of stilbite from 

 Poonah, that is compounded of a great number of individual crystals, 

 the terminations of which together make up an octahedral summit 

 with planes two inches wide. The color is a deep, rich salmon. 



Of the apophyllites from the same locality, one of the most beauti- 

 ful is a tabular square prism with the angles replaced by octahedral 

 planes, all of which are perfect in lustre and surface polish. The 

 crystal measures two and a quarter inches across, and is one and a 

 quarter inch in height. There are remarkable suites of pink apo- 

 phyllites from the Hartz, transparent green crystals, highly modified, 

 from Nova Scotia, and some of the finest of those crystals which 

 made the Erie tunnel through the trap-rock of Bergen Hill, New 

 Jersey, at one time so famous among mineralogists. It is frOm such 

 wonderful works as these that we are enabled justly to appreciate the 

 transcendent skill with which Nature performs her task when she 

 tries her hand at the plastic arts ; for example, what piece of statuary 

 could be so faultless, in grouping and finish, as one of these specimens, 



