﻿406 Scientific Intelligence. 



hydrogen sulphide, nearly all remaining in solution is thrown 

 down mixed with traces of copper, lead and zinc, separation from 

 the latter being especially difficult. The spark spectrum of the 

 metal austrium is characterized by two violet lines ; one of these 

 Aug a has a wave length 4165, the other Aus (5 has a wave length 

 of 4030. The former appears to coincide with the solar line 

 4164*7 of Angstrom. — Monatsch. Chem., vii, 121 ; JBer. JBerl. 

 Chem. Ges., xix, 431, July, 1886. 



4. On Holmium, Dysprosium and Gadolinium. — Lecoq de 

 Boisbaudran has submitted the earth called X by Soret, to a 

 hundred fractionings by means of ammonia and potassium sul- 

 phate, and has separated it into two portions. For one of these, 

 whose absorption spectrum exhibits the bands 640*4 and 536*3, he 

 proposes to retain the name holmium ; while for the other, con- 

 taining the bands 753 and 451*5 in its spectrum, he suggests the 

 name Dysprosium (from SvlnpoGiroS, difficultly accessible). 

 Subsequently he gives 804 (?) 756*5, 475, 451*3 and 427*5 as the 

 bands of dysprosium. In a letter to him, Marignac gives the 

 name Gadolinium to the element he has before indicated by Ya. 

 — G. B., cii, 902, 1003, 1005; Ber. Berl. Chem. Ges., xix, 388 

 (Ref.); J. Chem. Soc, 1, 667, August, 1886. 



II. Geology and Natukal Histoby. 



1. Geological Nomenclature: Meeting of the International 

 Committee at Geneva. — At the meeting of the committee of the 

 International Geological Congress on geological nomenclature, 

 at Geneva, in August last, Messrs. Capellini, the President, 

 Dewalqtte, Lapparent, Renevier and Vilanova were present. 

 A proof sheet of the proceedings, yet unfinished, has been received 

 from Mr. Dewalque, the secretary of the committee, and from it 

 the following abstract has been made out. 



The question as to the terms Silurian and Cambrian was, by 

 request from England, left for the next general session. 



The terms for the higher subdivisions were considered and the 

 following agreed upon, commencing with the highest: (l) Group-. 

 as, for example, the Primary, Secondary and Tertiary, correspond- 

 ing to Paleozoic, Mesozoic and Cenozoic. — (2) Sub-group : as 

 the Jurassic, Cretaceous. — (3) System : as the Liassic. — (4) Stage 

 (etage) : as the Sinemurian. — (5) Sub-stage. 



The word series was reserved for eruptive rocks, and for use in 

 a general way. For chronological terms, it was decided, on the 

 suggestion of M. Lapparent, that the correlate of Group should 

 be Era; of Sub-group, Time; of System, Period; of Stage, 

 Age ; of Sub-stage, Epoch. By this scheme we should have, for 

 example, the Mesozoic era, Jurassic time, liassic period, Sine- 

 murian age, and under the age, epochs. Renevier suggested the 

 use of sub-era in place of time, but Lapparent's proposition was 

 carried. 



