January 5, 1905J 



NA TURE 



fi-;incs), for a work concerning geology, or, failing that, 

 mineralogy; the Fontannes prize (2000 francs), for the best 

 publication on pahvontology ; the Alhumbert prize (1000 

 francs), for a memoir on the period of the last volcanic 

 eruptions in France. 



Ilotciny. — The grand prize of the physical sciences (3000 

 francsj ; the question proposed is the demonstration of the 

 various modes of formation and development of the egg in 

 the Ascomycetes and the Basidiomycetes. The Desmazi^res 

 prize (iboq francs), for the best \vorl< published during ihe 

 preceding year on Cryptogams; the Montagne prize (1500 

 francs), for worl': having for its object the anatomy, 

 physiology, development, or the description of the lower 

 Crvptogams ; the 'i'hore lyize (200 francs), for work on the 

 cellular Cryptogams of Europe. 



AiuUoniy and Zoology. — The Savigny prize (1300 francs), 

 for the assistance of young travelling zoologists, not re- 

 ceiving Government assistance, who have especially occupied 

 themselves with the invertebrates of Egypt and Syria. 



Medicine a}id Surgery. — A Montyon prize (2500 francs and 

 a mention of 1500 francs), for works and discoveries useful 

 in the art of healing ; the Barbier prize (2000 francs), for a 

 valuable discovery in surgical, medical, or pharmaceutical 

 science, or in botany having relation with medicine ; the 

 Bryant prize (100,000 francs), for the discovery of an absolute 

 specific against Asiatic cholera, or to point out in an 

 irrefutable manner the causes of Asiatic cholera, so that the 

 suppression of the disease will follow. Failing the award at 

 the capital sum, the annual interest will be given for ;i 

 rigorous demonstration of the existence in the atmosphen- 

 of matter capable of playing a part in the production <ii 

 propagation of epidemic diseases. The Godard prize (iumi] 

 francs), for the best memoir on the anatomy, physiology, 

 and pathology of the genito-urinary organs ; the Baron 

 Larrey prize (750 francs), for the best work dealing with 

 the subject of military medicine, surgery, or hygiene ; the 

 Hellion prize (1400 francs); the Mfege prize (10,000 francs); 

 the Serres prize (7500 francs), for a memoir on general 

 embryology applied as far as possible to physiology and 

 medicine ; the Dusgate prize (2500 francs), for the best 

 work on the diagnosis of death and the prevention of 

 premature burial. 



Physiology. — A Montyon prize (750 francs), and the 

 I'hilipeau.K prize (goo francs), for work in experimental 

 physiology ; the Lallemand prize (1800 francs), for work on 

 the nervous system ; the Pourat prize (1000 francs), for an 

 essay on the origin of muscular glycogen. 



Statistics. — A Montyon prize (500 francs), for a memoir 

 on French statistics. 



.\mong the general prizes offered in 1005 are the follow- 

 ing : — the Binoux prize (2000 francs), for a worlc on the 

 history of science; the Tr^mont prize (iioo francs), the 

 Gegner prize (3800 francs), the Lannelongue prize (1200 

 Irancs), the Wilde prize (4000 francs), the .Saintour prize 

 (3000 francs), the Petit d'Ormoy prizes (two of 10,000 

 francs), all for work useful in the promotion of .scientific 

 knowledge. Of these prizes those bearing the names of 

 Pierre Guzman, Lalande, Tchihatchef, l^a Caze, Delesse, 

 and Desmazi^res are especially mentioned as being awarded 

 without distinction of nationalitv. 



GEOLOGICAL NOTES. 

 A^ERY little geological information appears to have been 

 published on the .State of Durango, in western Mexico. 

 The observations therefore recorded during a brief journey 

 by Dr. O. C. Farrington are of considerable interest (Field 

 Columbian Museum, No. 89, geological series, vol. ii.. 

 No. 5). His route extended from the city of tiurango, 

 which is situated upon an alluvial plain hemmed in by low 

 and rugged hills, to the silver-mining town of \'illa Corona 

 cr X'entanas, distant about seventy miles in a direct line. 

 The ground, which forms part of the interior plateau of 

 Mexico, rises from about 6000 feet at Durango to 9000 feet. 

 While large tracts of the area are semi-arid and sparsely 

 covered with soil and vegetation, in some places corn is 

 successfully grown, and elsewhere there occur extensive 

 pine forests with oaks. Views of the scenery are given. 

 Eruptive rocks prevail, and near the Ciudad ranch, on one 

 <A the highest parts of the plateau, there is a tract of 



NO. 1836, VOL. 71] 



weathered masses known as La Ciudad de Rocas (" The 

 City of Rocks "). The outlines of the rocks are doined and 

 rounded, and they appear to be due to the weathering of 

 fairly homogeneous rhyolitic materials. 



Particular attention is directed by the author to the 

 famous Cerro Mercado or Iron Mountain, a hill largely 

 made up of solid iron-ore, and situated less than a mile 

 north-east of Durango City. It rises abruptly from the 

 alluvial plain to an average height of about 300 feet, with 

 single peaks 50 feet to 100 feet higher. The length of the 

 hill is about ig miles, and its average width about one- 

 third of a mile. The ore appears to be chiefly hajinatite, 

 although some magnetite also occurs ; in phvsical characters 

 it varies, being hard and soft, black, red, specular, and 

 earthy. Hard, solid black ore, however, forms the chief 

 mass of the " mountain," the black colour being in striking 

 contrast to the yellow and green of the surrounding plain, 

 The ridge is almost bare of vegetation, except for straggling 

 cacti, and its outline is bold and rugged. Steep cliffs 10 feet 

 to 20 feet high are not infrequent, and in places they exhibit 

 a distinct columnar structure like that of basalt (see Fig. i). 

 The existence of this hill appears to have been made known 

 in 1552 A.D., but the first serious attempt to work the iron- 



of Durango, Me 



ore was made in 1828. Successful operations were not 

 conducted until 1888, and only within the last five years 

 has a steady production been maintained. The amount of 

 ore exposed above the level of the plain is estimated at 

 360 million tons. The author briefly discusses the origin 

 of the iron-ore, regarding it as probably igneous. The 

 associated rocks of the district are rhyolites, probably of 

 later Tertiary age, but the relation, either in time or manner 

 of origin, between the associated eruptive rock and the 

 iron-oxide, and the origin of the iron-oxide itself, seem as 

 yet difficult to determine. 



A geological description of the Baraboo iron-bearing 

 district of Wisconsin, by Dr. Samuel Weidman, has been 

 issued bv the Wisconsin (jieological and Natural History 

 Survey (Bulletin No. 13, economic series No. 8). The area 

 is formed mainly by pre-Cambrian quartzites, which stand 

 out in bold north and south ranges, so connected both on 

 the east and west as to constitute a cordon of bluffs enclosing 

 a depressed drift-covered interior. Isolated areas of still 

 older rocks, rhyolite, granite, and diorite, occur along the 

 outer borders of the ranges. Potsdam sandstone is found 

 beneath the drift, and on the slopes of the Baraboo 

 quartzites, while later Pala-o^oic strata are met with at 

 higher levels. Special interest has recently been aroused by 



