GROWTH OF FUNERALS. ' 693 



s 



In the springs above enumerated, the reader has a sketch of a few of 

 those in Southern Nevada. The springs of this inhospitable region are so 

 few, that at one time or anotiier, each one becomes, as it were, the polar 

 «tar of the desert traveler, towards which he turns his"face with inflexible 

 •determination. — American Naturalist. 



GROWTH OF MINERALS. 



BY G. C. BROADHEAD. 



Your paper some time since, also of date 22d inst., contains notices of 

 Mr. Eedwin and mineral growth. Although his specimens must be quite 

 interesting forms of crystallization, still 1 do not see that his proof is con- 

 clusive — at least of a growth like unto that of either plants or auimals. 



Does he observe a mineral start from a root-stock, and gradually increase 

 and expand, both in length and breadth, like plants do when they receive 

 nourishment? Can minerals daring their growth (.') receive nourish- 

 ment like plants and animals, and vivify under the influence? If all 

 these things are proven, then his minerals may be said to grow ; and 

 when nourishment is withdrawn, they would lose their brilliancy, 

 •die and change their organic (?) structure. Do hix minerals do so? 

 If they do not then his theory is not proven. We all know that 

 by exposure, certain minerals oxidize more rapidly than others; but this 

 •could not be said to be loss of life, as understood among plants and animals 

 Nevertheless there are certain peculiarly interesting forms of crj'stalliza- 

 tion that rather puzzle us as to how or wh}^ they appear so. 



Minerals have their ovvn peculiar structure of crysta). Some at times 

 present a fibrous structure, w^hich may be likened to growth. 



Why is it that the Millerite occurs in extremely fine hair-like crystals 

 shooting as it were from the base of pearl spar crystals into and through, 

 calcite, as they do in specimens in my cabinet? Specimens show it starting 

 forth in divergent lines, and also somewhat fiisciculated. 



I also have specimens of needle-like crystals of Goethite radiating from 

 the base of caicite crystals, sometimes penetrating and passing through 

 them. I have them also penetrating quartz crystals. But a most interest- 

 •ing specimen in my collection is of smoky quartz from North Carolina. It 

 is of a deep rich color, yet beautifully transparent. It is about four inches 

 thick, but passing entirely through it is a fascicle of hair-like crystals of 

 rutile, .IJ inches wide by ^ inch thick. Other single hair-like crystals tra- 

 verse it in other directions, but are easily traced throughout. For these I 

 ■could detect no point of departure as in Goethite and Millerite. Very pret- 

 ty specimens are those from Cumberland, Rhode Island, of quartz showing' 

 acicular crystals of Hornblende traversing it in various directions, but each 

 ■seeming independent of the other. 



