86 Scientific Intelligence. 



ture, viz: niercur-amnionium salts. So far as yet known, the 

 qualitative composition is represented by the components Hg, N, 

 C1,S0 4 , probably O and possibly H. The tests, both qualitative 

 and quantitative, thus far made, seem to show, with little room 

 for doubt, that the mercury and nitrogen form the mercur-ammo- 

 nium radical. Dr. P. G. Nutting, of the Bm*eau of Standards, 

 has kindly examined spectroscopically the products of progressive 

 heating of the mineral under reduced pressure ; and besides 

 nitrogen, mercury, chlorine and sulphur, obtained a small amount 

 of helium. Singularly enough, this last seemed to come off 

 wholly during the first warming of the mineral and before it 

 underwent any visible breaking-up. 



The complete examination of this novel mineral and its associ- 

 ated mercury compounds will probably consume much time. In 

 order to reserve the field for the chemical examination by myself 

 and the crystallographical (now in progress) by Mr. W. T. 

 Schaller, this preliminary announcement is made. 



U. S. Geological Survey, Washington, D. C, 

 December 14, 1905. 



7. The Rodeo Meteorite. — The Rodeo meteorite, described by 

 O. C. FarrijSTGTon in the Publications of the Field Columbian 

 Museum (Geol. Ser., iii, No. 2), is an iron mass found about 1852 

 near the hamlet of Rodeo, Durango, Mexico. With this speci- 

 men the State of Durango has now yielded six meteorites, all but 

 one of them being masses of meteoric iron ; of these that known 

 as the Bella Roca was found at a point about forty miles distant but 

 though there are similarities in structure and in composition, they 

 are not enough to make a common origin probable. The Rodeo 

 meteorite is a medium octahedrite, with much schreibersite and 

 some graphite but no troilite was noted. An analysis by H. W. 

 Nichols gave the following results : Fe 89-84, Ni 8*79, Co 0-28, 

 Cu 0-07, P 0-80, S 0-02, C 0-09 =• 99*89. The high percentage of 

 phosphorus corresponds to the large amount of schreibersite 

 noted. For many years after the discovery of the iron, it was 

 made to do duty as an anvil at a forge and its present appearance 

 gives evidence of the use to which it was put. Its dimensions 

 are 12x9x8 inches. 



8. The Shelburne Meteorite. — A detailed account of the mete- 

 orite which fell near Shelburne, Ontario, on August 13, 1904, is 

 given by L. H. Borgstrom in the Transactions of the Royal 

 Astronomical Society of Canada for 1904 (pp. 69-94). The phe- 

 nomena connected with the fall were striking and were observed 

 at a large number of places in the neighborhood of Shelburne ; the 

 peculiar sound accompanying it, for example, was heard over an 

 area having a radius of 35 miles. Two independent stones were 

 found weighing respectively 13 lbs. and 28 lbs. ; they penetrated 

 in their fall about two feet into the ground. These specimens 

 conform to the general habit of such stones in the appearance of 

 the crust and pittings. A microscopic examination of the crust 

 showed that four zones could be distinguished : the outer black 



