170 J. F. KEMP — THE LEUCITE HILLS OF WYOMING. 



namely, the Italian volcanoes, especially Vesuvius, the Laacher See, and 

 the Kaiserstuhl in the Black Forest. Humboldt described the mineral 

 as essentially a European one. The introduction of the microscope? 

 and especially its employment by Zirkel in the preparation of his work 

 on the basaltic rocks,* brought to light a number of other localities in 

 Saxony, Bohemia, Thuringia, and the Rhon mountains,f all of which 

 were, however, European. In 1874 it was discovered by Vogelsang in a 

 basaltic rock from the small island of Bawean, north of Java, and the 

 announcement was made the next year by Zirkel, J the literary executor 

 of his friend Vogelsang, who had passed away in the meantime. Its 

 next discovery was in rocks from the locality that furnishes the subject 

 of this paper, and was announced in 1876 § by Zirkel, since which date 

 the following additional localities have been successively made known : 

 By Doelter,|| from Monte Ferru, Sardinia, in 1878, in a basaltic lava; by 

 Lorie, from the volcano Ringgit, in eastern Java, in 1879 ;1[ on Sao Antao, 

 one of the Cape Verde islands, by Doelter, ** in 1882, in a leucitite ; from 

 the volcano Moeriah, in central Java, by Verbeek and Fennema,tt m 

 1882 ; in northwest Persia by Pohlig, J J in 1884, in a leucitophyre ; from 

 the Cerro de las Virgines, in Lower California, by von ChrustschorT, §§ in 

 1884; in Argentina by G. Lallemand, || in 1884. So-called pseudo- 

 morphs of feldspar, after leucite, were reported from Magnet Cove, 

 Arkansas, by G. F. Kunz,1F1F in 1885, and were afterward investigated by 

 J. Francis Williams in 1890, by whom they were called pseudoleucites. 



* Untersuchungen iiber die mikroskopische Zusammensetzungen und Struktur der Basalt- 

 gesteine. 2 vols., Bonn, 1870. 

 t These statements are chiefly taken from volume vi of the Survey of the Fortieth Parallel, 



P- 259- 



X Neues Jahrbuch, 1875, p. 175. Compare also later citations of Verbeek and Fennema and of 

 Behrens. 



§ Survey of the Fortieth Parallel, vol. vi, p. 259, Microscopical Petrography. See also vol. ii, 

 p. 236, Description of occurrence, by S. F. Emmons. Zirkel gives the essentials of its microscopic 

 characters also in Berichte der Sachs. Gesellsch. der Wissenschaften, 1877, p. 238. 



|| Denkschriften der Wiener Akad. der Wissenschaften, vol. xxxix, 1878, p. 40. 



IfBijdrage tot de Kennis der javaansche Fruptief-gesteenten, Rotterdam, 1879, p. 247. See also 

 Behrens, Neues Jahrbuch, vol. ii, 1883, p. 60, and Natuurk. Verh. Kon. Vet. Akad., Amsterdam, 

 vol. xxiii, 1887. 



**Die Vulkane der Capverden und ihre Produkte, Graz., 1882, p 19. 



ft Neues Jahrbuch, Beilage-Band. ii, 1882, p. 169. 



XX Sitzungsberichte der Niederrheinische, Gesellsch. in Bonn, 1884, p. 98. See also regarding 

 leucite from Choi, Steinecke, Jungete Fruptivgesteine aus Persien, Inaugural Dissertation, Halle, 

 1887. 



§§ Tschermaks Mittheilungen, vol. vi, p. t6o. 



Illl Apuntos mineralogicos de la republica oriental, An. Soc. Cient. Argent., vol. xvii, p. 49, sqq., 

 Buenos-Ayres, 1884. The reference is on the authoi'ity of v. Chrustschofif as under 1890, later cited, 

 the original not being accessible to J. F. K. 



Tflf Proc. Am. Assoc. Adv. of Science, vol. xxxiv, 1885, pub. 1886 ; Am. Jour. Sci., vol. xxxi, 1886, 

 p. 74 ; analyses by Geuth ; microscopic examination by G. P. Merrill. The same occurrence was 

 leported to Rosenbusch by H. Carvill Lewis, Mikroskop. Physiographic, 1887, p. 631. J. Francis 

 Williams, Annual Rep. Ark. Geol. Survey, vol. ii, 1890, p. 267, and elsewhere in volume. Compare 

 also subsequent references under Derby, Hussak, and v. GraerF. 



