414 MEMOIRS NATIONAL ACADEMY OF SCIENCES, VOL. XIII. 



Of the twelve elements quantitatively determined by tlus analysis, aluminum, calcium, and potassium have been 

 rarely observed in meteoric-iron — meteors free from silicates — while the absence of copper, tin, manganese, and 

 sodium will be noticed. 



No room is left, it will be observed, by this analysis for any notable quantity of occluded gases, for which no search 

 was consequently made. 



The meteorite was investigated for included gases by Wright 4 who found as follows : 



C0 a CO H N Volumes 



At500° 19.98 13.52 60.92 5.58 0.65 



Atredheat 1.10 10.39 84.40 4.11 0.32 



13.64 12.47 68.81 5.08 0.97 



The amount of included gases as compared with other meteorites is small. 



In 1874 Smith, 5 on account of its high content of nickel, compared Shingle Springs with 

 Kokomo, Cape iron, and Oktibbeha. • 



Flight e stated that etching produces an irregular granular surface which under the glass, 

 on account of numerous small shiny points and lines, appears reticulated. He also, on account 

 of the absence of Widmannstatten figures and the high content of nickel, likens Shingle Springs 

 to the Cape iron. 



Brezina 7 in 1893 remarked upon the peculiar elongated bright etching spots which, after 

 etching, come out on the dark groundmass and, despite the irregular edging, show a parallelism 

 of the elongations. He thought that the rhabdite was oriented. 



Meunier 8 gave the following note : 



The Paris museum has quite a large section of this iron, which shows a very compact metal upon which the acid 

 produces no figures. The presence of nickel is doubtful. 



Brezina in 1895 grouped the meteorite among the Chesterville group of hexahedrites and 

 gave the following account of it : 



Shingle Springs has a peculiar twofold structure which leans to the ataxites in part. Upon etching there appear 

 in the groundmass elongated, irregularly bordered light etching streaks, whose longitudinal dimensions are parallel; 

 moreover the entire iron is interwoven with numberless small rhabdite laminae of from 0.1 to 0.2 mm. and occasionally 

 1.5 mm. in length without definite orientation. 



Cohen u gave an account of the history of the meteorite, and further studies. The latter 

 are as follows: 



A new chemical investigation seemed to me for many reasons desirable. On the one hand the previous analyses 

 vary considerably, and on the other hand Cairns gives a series of constituents which usually occur only in those iron 

 meteorites which include silicates. But on account of the small quantity of silica one could not refer these to the 

 percentages of potash, magnesium, calcium, and aluminum reported. Moreover, the material used by Cairns for 

 analysis (planings) was not free from objection. A section purchased from Ward was employed for an analysis by 

 O. Sjostrom. After dissolving a large quantity a small carbonaceous residue remained, but it contained no percept- 

 ible quantity of silica. Like negative results were obtained in testing for lime and magnesia in the portions used for 

 the determination of copper. Accordingly, further testing for copper and aluminum seemed to me unnecessary, espe- 

 cially as traces of these elements are difficult to prove if there has been necessity for the employment of a considerable 

 quantity of reagents. Since this was the case in Cairns 's analysis, as he employed 10 grams of material, it seemed to 

 me not impossible that the small quantities of Ca, Mg, Al, K, and Si0 2 which he found may have come from the 

 reagents or vessels used or from oils used in the cutting. A test for chlorine by Sjostrom gave also a negative result. 

 Sjostrom 's results were as follows: 



Fe Ni Co Cu Cr C P S 



82.21 16.69 0.65 0.02 0.02 0.03 0.34 0.05 =100.01 

 This gives the following as the mineralogical composition of the meteorite: 



Nickel iron 97. 65 



Nickel-iron phosphide 2. 21 



Iron sulphides 11 



100. 00 

 Thus the results obtained by Sjostrom and Cairns differ little, if the abnormal constituents reported by the latter 



be ignored. 



The specific gravity was determined by Dr. W. Leick on a section weighing 11 grams. This was found to be 



7.8943 at 21.9° C. The theoretical specific gravity from the constitution of the meteorite would be 7.9215. 



Since according to the statement of Silliman the Shingle Springs iron was preserved for a long time in a blacksmith 



shop, and it is to be supposed that attempts were made to work up the lump, I had Doctor Leick test its magnetic 



