462 MEMOIRS NATIONAL ACADEMY OF SCIENCES, VOL. XIII. 



A few silicate grains were mechanically isolated and identified as olivine, which occurs as 

 in the pallasite from Atacama, also in fine-grained aggregates. 



In the same year Genth 7 published a chemical analysis ; he announced that the iron was 

 not passive, as Shepard had stated, and conjectured a small quantity of labradorite. The 

 mean of three analyses by Genth follows under II. 



It is not certain which of the two masses were used in the analyses by Smith and Genth. 



Michler 8 named the locality of this meteorite Santa Rita (Santa Rica), and the mountain 

 at the foot of which Tuscon is situated, he named Sierra de Santa Catarina. 



In 1863, Brush 9 investigated a piece of the second mass mentioned and described by Parke 

 as an elongated prism in form, which was brought to San Francisco by Gen. Carleton. The 

 length of this mass was given as 124 cm. and the weight as 286§ kg. According to Brush, the 

 iron is active, has a specific gravity of 7.29, and appears flecked with particles of silicate; after 

 treatment with acid there remains a residue composed of partially disintegrated olivine, schrei- 

 bersite, and a trace of chromite. From this analysis (III below) the composition was esti- 

 mated as 89.62 per cent nickel iron and 10.07 per cent olivine, and it was noted that the 

 analysis of Smith, estimated in the same way, gave an olivine content of 8.70 per cent. Brush 

 conjectured that the piece analyzed by Smith came from the ring-shaped mass, which he desig- 

 nated as the "Bartlett meteorite." 



The above-mentioned analyses — I, Smith's; II, Genth's; and III, Brush's — are as follows: 



Rose ll described a section in the Berlin collection obtained from Shepard as follows : 



The polished surface is full of small round cavities. After etching it shows coarse-grained composite patches, 

 some of which in a certain light have a light gray, others a darker gray color; in other positions the shading is reversed. 

 The composite patches have a very thin edging of tanite, and many of the small cavities have glazed walls, which 

 are conspicuous upon the other dark surfaces. The composite surfaces show fine, linear, straight furrows, which have 

 a character somewhat different from the etching lines. 



Since the description agrees with those of others, except for the failure to mention the 

 occurrence of silicate, it would appear that this had been eliminated in cutting or polishing the 

 plate. 



In the same year as Brush, Haidinger 15 described the mass brought by Carleton to San 

 Francisco, under the name Carleton-Tucson and gave a reduced picture after a photograph 

 taken by Whitney. He compared the flat dish-shaped or shield-shaped form of the meteorite 

 with that of Hraschina and distinguished upon the specimen in the Vienna collection a smooth 

 portion of the surface and a part provided with pittings, and conjectured that the former was 

 the front part of the mass. Individual portions of J to 2 cm. in size show, according to Hai- 

 dinger, distinct metallic sheen, as well as occasional fine twin lamellae. He noted further, a 

 sort of a schistose structure, which was especially noticeable upon the two lateral surfaces, but 

 here curiously enough does not agree with their direction. The structure was described as 

 granular as a whole and imperfectly schistose in part. The etched plate appears crowned with 

 numerous, small stony particles, whose distribution is not entirely uniform. The meteorite, 

 he thought, should be designated as a "granular iron-stone." In a brief communication to 

 Haidinger, Richthofen gave the opinion that the analysis by Smith as well as that by Brush, 

 related to the Carleton iron, since the Ainsa iron had a different mineralogical composition. 

 It, he said, contains no olivine, but whitish crystalline grains, which he and Whitney regarded 

 as anorthite. For the latter ring-shaped mass Haidinger used the name "Ainsa-Tucson- 

 Meteorite." 



In 1863, the ring-shaped mass, which after the removal of several pieces weighed 635 kgs., 

 was also accessible, since it came as a gift to the Smithsonian Institution at Washington, 



