228 ROCHESTER ACADEMY OF SCIENCE. 



its boundaries Against taenite, apparently as products of cohesion of this latter. 

 Wrapping kamacite is rather broad, from 0.5 to 4 mm. in thickness. Taenite 

 is 0.05 to 0.2 mm. thick ; its borders to kamacite are often corroded and 

 replaced by chains of small schreibersites The plessite fields show in general 

 a confused mixture, rarely crystalline deliquifying. The olivine fills 58^ of the 

 cut face, nickel iron 38.77, schreibersite 1.^%. The volumes calculated with the 

 cubes of the square roots of these numbers and the specific gravities 3.4, 7.8, 

 7.2 respectively give the percentage of weight of olivine 41.5, nickel iron 50.8, 

 schreibersite 7.7. The position of this pallasite in the system is intermediate 

 between the Iniilac group and the Rokicky group. 



" Imilac and Marjalahti both show polyhedral olivine, but difYer from 

 Ilimaes by their double boundaries of taenite and by their crushed olivines, 

 while in the new pallasite the olivines seem wholly or nearly entire. Rokicky 

 and Admire have polyhedral olivines, which in Rokicky are entire as in Ilimaes, 

 while in Admire they are broken and dislocated, with nickel iron filling the dis- 

 tance between the parts. 



"Thus the nature of the olivine puts Ilimaes nearer to Rokicky than to 

 Imilac. The nickel iron on the contrary resembles more that in Imilac ; the 

 strong development of wrapping-kamacite, its puffy borders against the fields, 

 the lack of central skeletons, as well as the mode of occurrence of schreibersite 

 is the same in both meteorites. 



"With the pallasites of the Krasnojarsk group it holds few or no relations ; 

 of these pallasites only Alten (Finmarken) shows polyhedral olivines besides 

 rounded ones. 



"In summary, the new pallasite Ilimaes seem to be a distinct fall, 

 appertaining to the Rokicky group." 



With this important contribution from Dr. Brezina, we close 

 our notice of the structure and contents of the lUmaes pallasite. 

 We wish to add a word as to the provenance of the meteorite 

 in question. We have at the outset noticed the label upon the 

 Copiapo mass with the locality Imalaes, as there given. A fort- 

 night later, however, we met in the office of the Director of the 

 School of Mines in the capital city, Santiago de Chili, Seiior Don 

 Emeterio Moreno, introduced as the finder of the pallasite in 

 question, and as its donor to the Copiapo Museum. Sei"ior 

 Moreno told me of having himself found the meteorite about 1874 

 or 1875, at Ilimaes, on the desert of xA^tacama, about 12 leagues 

 to the south of Taltal. This point corresponds closely with the 

 locality of the Copiapo specimen, given me (in letter now before me) 

 by Professor Domeyko — "Latitude 26^, longitude 70°," though 

 he has labeled the mass Imalaes. Further, it is satisfactory to 

 find, in a description of an iron meteorite acquired for the Vienna 

 Museum in 1870, that Professor Tschermak notes that "the only 



