Sept. 21, 1888.] 



SCIENTIFIC NEWS. 



327 



my address was already printed. I therefore confine 

 myself to a mention of it, while for my information I 

 had recourse to the independent notices of MM. Renevier, 

 Klebs, Choffet, Frazer, Blanford. and Dewalque. At 

 Berlin the Congress was especially engaged upon the 

 geological map, the committee of which, profiting by the 

 liberty accorded by the Bologna Congress, revised the 

 colours for the sedimentary rocks in the following 

 manner: — 



I. 



Actual deposits (Allu- 







vium, etc.) . 





Very pale cream colour. 



2. 



Quaternary (D 



iluvium) 



Naples yellow. 



3- 



Tertiary 



. . 



Different shades of yellow 



4- 



Cretaceous 



. . . 



Green tints and hatchings 



5- 



Jurassic 



■ . • 



Blue tints. 



6. 



Triassic 



• . • 



Violet tints and dots. 



7- 



Permian and 



Carbon- 







iferous 



. . 



Grey tints and hatching. 



8. 



Devonian 



• ■ . 



Brown tints. 



9- 



Silurian 



■ . ■ 



Greenish-grey tints. 



0. 



Archean 



• . ■ 



Rose tints. 



And for the ten divisions of the eruptive recks different 

 tints and dots of strong and brilliant red. 



With respect to the letters used in addition to the tints, 

 it was decided to employ Latin initials for the sedimentary 

 rocks and Greek initials for the eruptive rocks. It is on 

 the basis thus described that the large and beautiful 

 geological map of Europe in course of preparation at 

 Berlin will be coloured. 



As to the stratigraphical uniformity, the Congress 

 adopted in the main the resolutions passed at Bologna. 

 The French and Portugese committees, however, pro- 

 posed to replace the word " Group" by "Series" for the 

 three great divisions of the earth's crust, so that in place 

 of " Primary Group," &c, we should have " Primary 

 Series." The word " Group " will then take the place 

 of the divisions of systems, as " Oolitic Group " (instead 

 of " Series "). This substitution will, perhaps, re- 

 commend itself to many among ourselves. 



Further, on the proposition of substituting for the 

 present different terminations, a system of termina- 

 tions, in ique, the Committees were not unanimous. 

 Instead of Eocenic System, &c, we should have 

 the terms Eocenic, Siluric, &c. Is it essential to alter 

 these ancient terms of the science ? It is all 

 very well to have such terminations for actual 

 things, such as the crystalline and eruptive rocks, e.g., 

 granitic or porphyritic rocks, but can one submit, or is it 

 necessary to submit, series of strata which have no 

 character in common, to the same narrow rule, because 

 they are all included under the same ideal name of 

 classification ? This question will no doubt be discussed, 

 and it is for you, gentlemen, to judgo what is the 

 most fitting solution. 



Among the other questions, gentlemen, which you 

 will have to consider, is that of the classification of 

 the Cambrian and Silurian strata. Accordingly as these 

 two great systems have been taken in a descending or an 

 ascending order, the division between the two has been 

 placed lower or higher, because the breaks in the two 

 groups are few and the palaeontological connection is 

 little interrupted. In England, Sedgwick, who began 

 from below, found no break till he reached the Mayhill 

 sandstone, while Murchison, who began from above, 

 met with no check till he reached the lower limit of 

 palaeozoic life : he even hesitated. Thus, in the countries 



where Murchison's work is best known and where his 

 lead has been followed, the partisans of one side have 

 surmounted stratigraphical barriers, while the partisans 

 of the other side have neglected palaeontological argu- 

 ments. In this country, their stratigraphy al birthplace, 

 the Cambrian and Silurian have been but little spread 

 out, and it is only since the death of their founders 

 that the palaeontological proofs have increased suffi- 

 ciently to indicate their distinctive character. These 

 two systems are found elsewhere (especially in 

 America, where there is now some discussion as to their 

 association with a Taconic system) either more developed 

 or with special characteristics which may enable ns to 

 determine more precisely their mutual relations. Here, 

 too, gentlemen, the knowledge which you bring from 

 all parts of the world may assist us to unravel this 

 complicated question. 



Amongst the other subjects which the previous Con- 

 gresses have not fully discussed are : — 



(1) The connection between the Carboniferous and the 

 Permian. 



(2) Between the Rhaetic and the Jurassic. 



(3) Between the Tertiary and the Quaternary. 



In the case where there has been no interruption of 

 the layers or discordant stratifications, the systems 

 pass from one to the other without an apparent break, 

 like the colour of the solar spectrum ; but, as everybody 

 knows, if a link be missing, the sequence is broken and 

 the line of separation of the divided layers is settled. 

 If, for example, the Cnradoc were missing from the 

 Cambrian-Silurian, or if the Pliocene were missing from 

 the Tertiary, there would exist between these formations 

 a gap which would give the necessary break. 



Apart from the international questions, the Congress 

 of Berlin had several special memoirs under considera- 

 tion, but as yet the details are not before us; besides, 

 whatever may be their importance, they are less inter- 

 esting for the moment than the international subjects 

 under discussion. One of these special memoirs refers 

 to a vast palaeontological project, and the Congress has 

 nominated a Commission of distinguished palaeontolo- 

 gists to contribute to its realisation. The proposed 

 work is on the plan ofBronn's "Enumerator and Nomen- 

 clator," and of Alcide d'Orbigny's " Prodrome ; " but such 

 is the progress that palaeontology has made, that about 

 fifty large volumes would be needed for the complete 

 enumeration of all the known animal and vegetable 

 fossils. A work of this nature would form a useful 

 addition to the great polyglot dictionary of geological 

 terms projected at Bologna. 



These then, gentlemen, are some of the subjects which 

 you will have to consider. You have to review, and 

 where possible to finally decide, questions already dis- 

 cussed, and to examine the new points raised. Amongst 

 them is the fundamental problem of the crystalline 

 schists, a subject remarkable for the great progress made 

 in it during the last few years, and for the new aspect 

 which it has recently assumed; for it is clear now that 

 it isnot merely a chemical metamorphosis by heat, but that 

 the subject also includes questions of weight, pressure, 

 and of sliding movements which necessitate for their ex- 

 planation the combined efforts ol the physicist, tha 

 chemist, the petrologist, and the stratigrapher. 



Although the majority of the subjects under considera- 

 tion at the Ipresent Congress are eminently practical and 

 positive, they include theoretical points of the greatest 

 interest. The classification of the formations, and their 



