304 



SCIENCE. 



[N. S. Vol. XVIII. No. 453. 



and transparent, are found. The three char- 

 acteristic varieties of the latter are a clear 

 yellow gem spodumene of Brazil,* the green 

 hiddenite or ' little emerald ' of North Caro- 

 lina,! and the lilac sometimes found in Con- 

 necticut.:): These are without doubt remnants 

 of large specimens, which must have been ele- 

 gant. Spodumene is very subject to altera- 

 tion and has usually lost all its transparency 

 and beauty of tint. 



Kunz (loc. cit.) described some large and 

 magnificent crystals of unaltered spodumene, 

 of rich lilac color, which have recently been 

 discovered near Pala, San Diego County, Cali- 

 fornia, in connection with certain other lithia 

 minerals. It has been my good fortune to see 

 and handle from this locality massive spodu- 

 mene crystals (10 X 20 X* cms.) perfectly 

 clear, of a rose lilac tint, varying with the 

 spodumene dichroism, from a very pale tinge 

 when observed transversely to the prism, to a 

 rich amethystine hue longitudinally. No such 

 crystals of spodumene have ever been seen be- 

 fore and the discovery is of great mineralog- 

 ical interest. The crystals have been etched 

 by weathering and have a twinning like the 

 hiddenite variety. The mineral, when cut and 

 mounted parallel to the base, gives gems of 

 great beauty. The chemical analysis, which 

 is under way in my laboratory, will shortly 

 be published. 



The observations of Dr. Kunz suificiently 

 characterize this mineral of peculiar beauty 

 as a new gem, which he has not named. I 

 have submitted large crystals to the action of 

 ultra-violet light without any evidence of 

 fluorescence or phosphorescence. When sub- 

 jected to bombardment of the Rontgen rays of 

 high penetration for several minutes no fluor- 

 escence is observed, but on removal to a dark 

 chamber it exhibits a persistent white lumi- 

 nosity not observed with this class of minerals, 

 as learned by experiments with altered and 

 unaltered spodumene from the localities men- 

 tioned, including cut stones and such hand- 

 some crystals of hiddenite as afforded by the 

 collections mentioned. I have been able to 



* Pisani, Comptes Rendus, 84, 1509, 1877. 

 t J. L. Smith, Am. J. Soi., 21, 128, 1881. 

 t Penfield, Am. J. 8ci., 20, 259, 1880. 



excite a crystal (2X4X10 cms.) by the action 

 of the X-rays for five minutes sufficiently to 

 cause it to photograph itself when subse- 

 quently placed directly upon a sensitive plate 

 (thin white paper being interposed) and al- 

 lowed to remain in an especially constructed 

 padded black box in a dark room for a period 

 of ten minutes. The material is penetrated 

 by the rays as shown by a cathodograph. The 

 excitation is not superficial, but persists 

 throughout the mass. On account of this 

 unusual and characteristic phosphorescence, as 

 well as the other properties, I propose the 

 name Kunzite, for reasons unnecessary to give 

 to American and European scientific men. 

 The mineral material and cut gems may be 

 seen at Tiffany and Co.'s or the American 

 Museum of Natural History, New York. 



Ch.\RLES B.\SKERyiLLE. 



August 12, 1903. 



THE TOXIC EFFECT OF H AND OH IONS ON SEED- 

 LINGS OF INDIAN CORN. 



Within the last five years or so some at- 

 tempt has been made to determine the toxic 

 effect of various chemical solutions upon plant 

 life. This involved the theory of ionization, 

 which is based upon the electrical conductivity 

 of solutions. 



When acids, bases or salts are put into solu- 

 tion, they separate, more or less completely, 

 into molecules or part molecules of their ele- 

 ments, or into groups of two or more atoms 

 of different elements which are very strongly 

 united. Molecules which exist in this state 

 are known as ions — e. g., if 100 molecules of 

 HCl were put into solution they would sep- 

 arate to form H ions and CI ions, and prob- 

 ably there would be some HCl ions left, de- 

 pending upon the strength of the solution, 

 n NaOH were put into solution a like separa- 

 tion would take place except that OH ions 

 and Na ions would be formed in place of the 

 H ions and CI ions. 



All compounds do not permit total dissocia- 

 tion at the same dilution. " Solutions of 

 hydrochloric, nitric and sulfuric acids are 

 nearly completely dissociated when an equiva- 

 lent in grams is dissolved in 1,000 liters of 



