316 Scientific Intelligence. 



4. JBacuhirlto, the Great Meteorite of Siiialoa, 3Iexico. — An 

 interesting account is given in vol. iv (pp. 67-V4) of the Proceed- 

 ings of the Rochester Academy of Science, by Hexry A. Ward, 

 of a visit to the gigantic mass of meteoric iron discovered in 

 1876 in the State of Sinaloa, Mexico. This is perhaps the largest 

 of all known meteorites ; its weight is roughly estimated at 50 

 tons, and its only rival is the meteorite of Anighito, Greenland, 

 to which a recent estimate has assigned a weight of 46^ tons. 

 The three meteorites most nearly approaching these are those of 

 Bemdego, Brazil, 5^ tons; of San Gregorio, Mexico, 11^ tons, 

 and Chupaderos, Mexico, 15f tons. The dimensions of the Bacu- 

 birito meteorite were measured, after extensive excavations of 

 the soil in which it was nearly imbedded, as follows: length, 13 

 feet 1 inch ; width 6 feet 2 inches ; thickness, 5 feet 4 inches. 

 The shape is extremely irregular, being compared to that of a 

 ham ; the cubic contents consequently could be only approxi- 

 mately estimated. In composition, an analysis by Whitfield has 

 shown it to contain about 7 per cent nickel, and its structure is 

 eminently octahedral. The exterior shows little oxidation and 

 the pittings are clean and sharp in outline. It is to be hoped 

 that the Mexican Government, which with admirable liberality 

 has already transferred to the School of Mines, Mexico, five of 

 her largest meteorites, may also undertake the similar protec- 

 tion of this unique mass. 



5. The Origin of Eskers ; by W. O. Crosby. Boston Soc. 

 Nat. Hist., vol. 30, No. 3, pp. 375-411. — It is an accepted 

 truth among glacialists that eskers are formed either by super- 

 glacial or subglacial streams, and the large majority of geologists 

 believe they are of subglacial origin. Professor Crosby has 

 reexamined the whole subject and concludes that streams flowing 

 upon the ice sheet rather than those flowing under it are respon- 

 sible for most of the esker ridges. 



6. TJeher Hussakite (Xenotim) iind einige andere seltene 

 ge&teinhildende Min er alien ; by H. Rosler. Zeitschr. f. Kryst., 

 xxxvi, pp. 258-267. — Prismatic xenotime (hussakite) has been 

 identified in the heavy residues of a large number (52) of 

 European rocks and kaolins amongst the crystals usually referred 

 to zircon, from which it was distinguished in part by the applica- 

 tion of the magnesium test for phosphoric acid ; in part by the 

 hepar reaction for sulphuric acid with soda on charcoal, but for 

 the most part by the difference in the strength of the double 

 refraction in microscopic preparations. Owing to the elusive 

 nature of all these tests when applied to microscopic crystals in 

 microscopic quantities, it seems desirable to carefully verify these 

 identifications before conclusions of such far-reaching conse- 

 quences be definitely accepted. 



Contrary to the observations of Derby, who only identified 

 prismatic xenotime in a single case in scores of residues examined 

 and who found the octahedral forms almost invariably accom- 

 panied by monazite, the author finds, in the rocks examined, the 



