Xll OBITUARY NOTICES. 



studied geology in Heidelberg. A second geological paper 

 appeared during the same year with the title " Alter verschiedener 

 Zechsteine;" and in 1848 he published two similar papers in the 

 Jahrbuch, entitled respectively " Eocene Schichten mit Beschrei- 

 bung der Petrifacten " and " Miocene Geognosie des Mainzer 

 Beckens." 



It was in Giessen, however, under the influence of Liebig, and 

 particularly in Marburg, where he studied with Bunsen, that Dr. 

 Genth's mind received its strong bias in the direction of chem- 

 istry. Even in 1845, before taking his Doctor's degree, he pub- 

 lished papers on " Prehnite, a Pseudomorph after Analcime;" on 

 " Chemical Examination of Masopin, a new Gum-resin," and on 

 "The Analysis of Various Refined Coppers." Two manuals by 

 him — one a "Tabular Review of the More Important Reactions of 

 Bases," and the other a similar work en the Acids — appeared soon 

 after his graduation. 



The purely chemical papers of Dr. Genth number in all thirty- 

 one. In a letter to Liebig in 1845, an( * published in the Annalen, 

 he called attention to an allotropic modification of nickelous oxide, 

 occurring in the form of small, almost microscopic crystals, grayish- 

 black in color, and having the form of regular octahedrons, on certain 

 disks of refined copper from Riechelsdorf. In 1853 ne discovered 

 the corresponding compound of cobalt, which closely resembled it. 



In Liebig s Annalen for 1848, Dr. Genth published a paper giving 

 analyses of lavas from Hecla, which had been collected by Bunsen 

 during his visit to Iceland. Four of these lavas were examined, 

 those from Thjorsa, Hals and Efrahvolshraun and that of the erup- 

 tion of 1845. I n tne nrst of these he found his first new mineral, 

 which he named Thjorsaite.* The author concludes: (1) That 

 these lavas differ from those of Vesuvius and Etna in that they are 

 insoluble in hydrochloric acid, containing no material gelatinizing 

 with this acid ; (2) that the essential constituent in them has the 

 same composition as wichtisite ; and (3) that any differences in 

 composition between them are due to the admixture of thjorsaite, 

 chrysolite, orthoclase (?) and magnetite. 



In Erdmanri 1 's Journal filr praktische Chemie for 1846 appeared 

 an elaborate paper by Dr. Genth on a " Chemical Exam- 

 ination of the Products obtained in the Metallurgy of Copper 

 Schists." The Friedrichs plant at Riechelsdorf was especially 



* Subsequently shown to be Anorthite. 



