March, 1907. Iron Meteorites — Farrington. 61 



judging the meteoric origin of a body. Cobalt was reported by 

 Stromeyer in the iron meteorite of Cape of Good Hope in 1816,* and 

 copper by the same investigator in 1833.J Stromeyer expressed the 

 belief that copper was, with cobalt, a constant ingredient of meteoric 

 nickel-iron, and this conclusion was later corroborated by SmithJ on 

 the basis of more than one hundred analyses. Chromium was dis- 

 covered as a component of meteoric nickel-iron by Laugier in 181 7. § 

 The presence of manganese and tin in meteoric nickel-iron was also 

 early reported. The presence ot other metals or semi-metals reported 

 at different times, such as zinc, lead, arsenic, and antimony, has not 

 been confirmed, while the presence of aluminum, calcium, magnesium, 

 potassium, and sodium, noted by several analysts, is doubtless to be 

 referred to small quantities of silicates which either formed a constitu- 

 ent of the meteorite, as in Tucson, Tula, etc., or accidentally contami- 

 nated the material analyzed. The occurrence of phosphorus in me- 

 teoric nickel-iron seems first to have been noted by Berzelius Ij in the 

 undissolved residue of Bohumilitz. It was similarily reported by 

 analysts who followed Berzelius, but percentages were not commonly 

 given until later times. Sulphur was early noted as an ingredient of 

 meteoric stones and later of irons. Since it occurred as a soluble 

 constituent, it was more often reported in the early analyses than 

 phosphorus. The presence of carbon as graphite was noted by Ten- 

 nant*' in 1806 in the Cape of Good Hope meteorite. Being, like the 

 phosphides, insoluble, its presence was often later reported in insolu- 

 ble residues, but its amount was rarely given. Silicon, as reported in 

 the earlier analyses, whether as metal or oxide, is probably for the 

 most part to be referred to accessory silicates. With later methods, 

 however, its detection in small quantities as an ingredient of the 

 nickel-iron has become possible. The first detection of chlorine as 

 an essential constituent of iron meteorites seems to have been by Jack- 

 son in 1838,** in the meteorite of Limestone Creek. Its presence has 

 been occasionally but not commonly reported by later.analysts. Deter- 

 minations of specific gravity of the iron meteorites examined seem to 

 have been common. While these are probably for the most part fairly 

 reliable, some of the values reported are too anomalous to seem 

 trustworthy. 



* Gottingisclie Gelehrte .\nzeigen, 1816, 2041-2043. 

 t Gottingische Gelehrte .Anzeigen, 1S33, 369-370. 



i Am. Jour. Science, 1870 (21, 49, 332. 

 'f, Ann. Chem. Pharm., 1817, IV, 363-366. 

 ! Pogg. Ann., 1S32, XXVII, 128-132. 



* Tillochs Phil. Mag., London, 1806. XXV, 1S2. 

 ** Am. Jour. Science (i), 34, 332-317. 



