778 



SCIENCE. 



[N. S. Vol. XVIII. No. 4G8. 



similar exceptional results appear, as in 

 Mono Lake, of the presence of some rare 

 element (perhaps new) widely diffused in 

 very minute quantities. 



A similar indication is given by the be- 

 havior of the glauberite ; those from Borax 

 Lake, California, phosphoresced, as did 

 those from Laramie and from Spain; while 

 Chilian specimens did not. 



18. It is notable that tourmaline, which 

 is so markedly pyroelectric, gave no re- 

 sponse; nor did beryl, save in three speci- 

 mens from Haddam Neck, Conn. 



19. American sapphires of various kinds, 

 spinel, chrysoberyl, and almost all jades, 

 declined to show any effects from ultra- 

 violet rays. Most of the gem-minerals, ex- 

 cept diamond, opal and kunzite, were little 

 acted tipon. 



20. Only two of the rare earth oxides re- 

 sponded at all to the action of ultra-violet 

 rays, namely, zirconium and thorium diox- 

 ides, which phosphoresced strongly. The 

 thorium dioxide remained luminous in the 

 dark for a greater length of time. The 

 zirconium dioxide showed no radio-activity 

 when tested by the electrical and photo- 

 graphic methods. It is strange that the two 

 rare earths forming dioxides are the only 

 ones to exhibit this property. The follow- 

 ing oxides were examined: yttrium, ytter- 

 bium, erbium, gadolinium, samarium, 

 lanthanum, cerium, neodidymium, praseo- 

 didymium, thorium, zirconium, titanium, 

 uranium and variable mixtures of the same. 

 Thej' will be investigated further by one 

 of us. (B.) 



In view of the fact that these two 

 earths give this characteristic response to 

 ultra-violet rays, it became immediately of 

 interest to learn the effect of these rays 

 upon minerals carrying those substances 

 in different proportions. The following 

 selected minerals were subjected to the 

 action of ultra-violet rays without a single 



one of them giving either fluorescence or 

 phosphorescence. 



Samarskite. — Berthier Co., Que. 



Thorite (Orangite). — Arendal, Norway. 



Thorite. — Barkevik, Norway. 



Thorite (Auerlite). — Green River, N. C. 



Sipylite. — Amherst Co., Va. 



Columbite. — Portland, Conn. 



ilonazite. — Arendal, Norway ; Zlatoust, Ural ; 

 171st St. & Waslm. Ave., N. Y., Amelia Court 

 House, Va., Alexander Co., N. C. 



Monasite sand. — Rio, Brazil. 



Monazite. — Tvedestrand, Norway. 



Xenotime. — Cheyenne CaSon, Colo.; Alexander 

 Co., N. C. ; Hitteroe, Norway. 



Euxenite .(in .Samarskite). — Mitchell Co., N. C. 



^lEschynite. — Hitteroe, Norway. 



Polycrase. — Near Marietta, S. C. 



Fergusonite. — Llano Co., Texas; Ytterby, 

 Sweden. 



TENTATIVE CONCLUSIONS. 



1. It seems as though in willemite, 

 hydrozincite and the artificial phos- 

 phorescent zinc sulphide and zinc oxide, 

 there is present, with the zinc, some ele- 

 ment probably not yet determined, that 

 possesses peculiar properties; one that 

 in combination with a zinc mineral gives 

 the high luminosity by the application of 

 radium, the ultra-violet rays, or the Roent- 

 gen rays or other radio-active bodies; an 

 element possibly accompanying zinc and 

 possessing an affinity for it, as polonium 

 has for bismuth, perhaps Phipson's actin- 

 ium mentioned above. 



2. It seems likely also that there exists 

 in fluorspar either yttrium or ytterbium, 

 or some other related rare earth, or per- 

 haps several of them, from the variable ac- 

 tion of this mineral with the various kinds 

 of rays. 



3. In the ease of the numerous minerals 

 coming from Borax Lake, so various in 

 composition and yet all responsive alike 

 to ultra-violet rays, there seems to be pres- 

 ent some element which is very highly 

 active, but is not responsive to radium, 

 and which appears in every single mineral 



