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.¢ Stromeyer expressed the 
belief that copper was, with cobalt, a constant ingredient of meteoric 
nickel-iron, and this conclusion was later corroborated by Smith{ on 
the basis of more than one hundred analyses. Chromium was dis- 
covered as a component of meteoric nickel-iron by Laugier in 1817.§ 
The. presence of manganese and tin in meteoric nickel-iron was also 
early reported. The presence of 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 | 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 lateranalysts. 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. 
* Gottingische Gelehrte Anzeigen, 1816, 2041-2043. 
+ Gottingische Gelehrte Anzeigen, 1833, 369-370. 
t Am. Jour. Science, 1870 (2), 49, 332. 
2 Ann. Chem. Pharm., 1817, 1V, 363-366. 
|| Pogg. Ann., 1832, XX VII, 128-132. 
“ Tillochs Phil. Mag., London, 1806, XXV, 182. 
** Am. Jour. Science (!), 34, 332-337. 
