November 20, 1891. J 



SCIENCE. 



291 



One of the most interesting matters presented at these meetings 

 was the paper of Mr. Charles D. Walcott on the discovt ry of un- 

 doubted fish-remains in strata of Ordovician (Lower Silurian) age, 

 near Caiion City, Colorado. The occurrence of fishes in Upper 

 Silurian beds has long been known in Europe, and in a few cases 

 in this country; but it was a novel, and almost startling, change 

 in our ordinary ideas to see these specimens of abundant ichthyic 

 remains, — chiefly small granoidal plates and scales, — from a hori- 

 zon corresponding to the Trenton limestone of the East. 



The library of the Columbian University was converted into a 

 room for geological exhibits, in which were arranged a very large 

 number of specimens and appliances of much interest. The 

 United States Geological Survey furnished a host of maps, reports, 

 reliefs, photographs, etc., illustrating important features of Ameri- 

 can geology and the extensive character of the work in progress 

 therein. Numerous maps and volumes were likewise displayed 

 by State surveys, and by individual geologists; while many re- 

 markable specimens and suites of specimens occupied table-cases 

 throughout the room. Among these may be mentioned an exten- 

 sive series of American rocks, brought by the representatives from 

 that country; the Ordovician fish-remains above referred to, by 

 Mr. Walcott; a most beautiful suite of the Tertiary insects from 

 Florissant, Colorado, named and described by Professor Scudder; 

 and, of peculiar interest, what appeared to be unquestionably 

 glacial groovings from a Silurian rock-surface, exposed on removal 

 of overlying sti'ata, — thus indicating a glaciai epoch far back in 

 early Paleozoic time. These specimens, with views of the spot, 

 were from a Scandinavian locality. Most of this interesting ma- 

 terial was recorded in a pamphlet "Catalogue of Exhibits." 



The general plan of the Geological Congress was to take up, for 

 each day of the session, some one comprehensive subject, and 

 after a full treatment of it by one or two members, to discuss it 

 broadly and compare views, but not to attempt to decide upon 

 mooted question?. This method was the result of experience in 

 past meetings of the Congress, wherein it has come to be seen that 

 little is gained by the attempt to pass judgment or formulate rules. 

 Another interesting point was that, by general consent, the lead 

 was taken by, or rather given to, our own geologists, — the foreign 

 delegates, while participating largely in the discussions, coming 

 to see, and hear, and learn. 



The first subject was the classification of Pleistocene (Quater- 

 nary) deposits. The opening paper was by president T. C. Cham- 

 berlain, and was a comprehensive and exhaustive scheme of genetic 

 classification of all the forms and types of superficial deposits im- 

 mediately preceding the present period. The second day was 

 given to the topic of cerrelation of sedimentary rocks, and was 

 opened at length by Professor G. K. Gilbert of the United States 

 Geological Survey, who described the several methods, both physi- 

 cal (by structure) and biotic (by fossils) available in identifying 

 and correlating rocks. The discussion on this topic became very 

 extended, going over into the next day, and was of great interest, 

 in that many specialists in diflferent departments presented their 

 methods of work and their estimates of various means. Thus 

 Professor von Zittel dwelt on the advantages of marine inverte- 

 brates, as compared with higher forms, or correlation ; Professor 

 Cope took up the gauntlet in behalf of vertebrata; and Dr. Lester 

 F. Ward for fossil plants; while the physical methods of corre- 

 lating and classifying strata were discussed by Professor McGeein 

 an exposition of what is sometimes termed " the new geology," as 

 applied to the coastal region of the Atlantic States, and by Pro- 

 fessor Van Hise in a discussion of the great pre-Columbian series, 

 now coming to be recognized and traced in the United States, un- 

 der the name of Algonkian. The general view, however, empha- 

 sized the fact that all methods of correlation vary in value inversely 

 as the geographical distance of the beds. 



The' next day was given to map-coloring and cartography. Here 

 Major Powell, the head of the United States Geological Survey, 

 naturally led the discussion, presenting a full account of the 

 scheme adopted for the work of the survey, which is quite different 

 from that proposed in 1885, at the Berlin meeting of the Congress. 

 In the subsequent discussion, one fact, very strikingly developed, 

 was the vastness of the scale on which the work of the American 

 survey is conducted, as compared with those of Europe. 



Indeed, this same aspect came often and strongly to view during 

 the summer,— the immense field of geology in America, the vast 

 areas to be connected and compared, the possibility of both 

 methods and resulls, when "the whole boundless continent," — of 

 simple structure, and under a single government, — is to be dealt 

 with, that are different from those of the Old World, — broader, 

 grander, and more comprehensive. D. S. Mabtin. 



New York, Nov. 14. 



Fifth International Congress of Geologists. 



In the current number of your journal (Nov. G, 1891) is an arti- 

 cle presenting Dr. Persifor Frazer's views upon the recent meeting 

 of the International Congress at Washington. Dr. Frazer is of 

 course at liberty to entertain such opinions with regard to the 

 congr^ess as he pleases, but in presenting an elaborate statistical 

 table, as he has done here, he should at least endeavor to obtain 

 accurate data. 



Printed lists of names and addresses of members who had reg- 

 istered up to the fourth day of the congress were freely distrib- 

 uted to all wbo took part in the meetings. Some few belated for- 

 eigners registered after that date. Dr. Frazer's table ostensibly 

 gives the comparative attendance at the five congresses, although 

 he himself admits that no statistics have been given showing the 

 actual attendance at the Paris congress. For the Washington 

 congress he gives an attendance of 148 natives and 58 foreigners, 

 as against 172 natives and 75 foreigners given by the printed lists 

 above mentioned. Hence, of the four conclusions which he 

 draws from his table, in point of fact all are incorrect, with the 

 possible exception of the last, which I have not yet had time to 

 verify. S. F. Emmons. 



Washington, D.C., Nov. 12. 



AMONG THE PUBLISHERS. 



Early in 1892 Houghton, Mifflin, & Co. will publish under 

 the title of " The Spirit of Modern Philosophy," the lectures given 

 by Dr. Josiah Eoyce of Harvard in Cambridge last winter. The 

 lectures were listened to with great interest, and, having been 

 carefully revised, will form a work of remarkable value, 



— Little, Brown, & Co. have nearly ready a new edition of 

 Nuttairs " Hand-book of Amex-ican Ornithology," brought down 

 to date by Montague Chamberlain. 



— A "Supplement to the Hand-Book of the American Academy " 

 has just been published. It contains a list of the accessions to 

 membership in the American Academy of Political and Social Sci- 

 ence from Apr. 15 to Aug. 15, 545 names in all. 



— Dextrine is the best substance for gumming labels. It may be 

 purchased of almost any wholesale manufacturing chemist. It is 

 mixed and stirred with boiling water until it obtains a cousistency 

 like ordinary mucilage, then apijlied to the back of the printed 

 matter with a wide camel's-hair brush (care being taken to use 

 paper that is not thin or unsized) -f after it becomes dry it is fit 

 for use, being rendered exceedingly adhesive by a slight wetting. 



— C. A. Starke, Gorlitz, Prussia, has just published, says The 

 Publishers' Weekly, the first number of Ex-libris, a journal de- 

 voted to the interests of collectors of bookplates in particular and 

 to bookish matters in general, to be issued as often as the material 

 in hand warrants making up a number. The first issue is almost 

 entirely devoted to the subject-matter which gives the journal its 

 title. It is a small quarto and handsomely printed. 



— • To extract grease spots from books or paper, gently warm the 

 greased or spotted parts of the book or paper and then press upon 

 it pieces of blotting-paper, one after another, so as to absorb as 

 much of the grease as possible. Have ready some fine, clear es- 

 sential oil of turpentine, heated almost to a boiling state; warm 

 the greased leaf a little, and then with a soft, clean brush wet the 

 heated turpentine both sides of the spotted part. By repeating 

 this application the grease will be extracted, according to The 

 Publishers' Weekly. Lastly, with another brush dipped in recti- 

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 longer appear, neither will the paper be discolored. 



