64 MEMOIRS NATIONAL ACADEMY OF SCIENCES, VOL. XIII. 



crystals of aulphuret of chromium (schreibersite resembling allanite in form and color) are occasionally visible. Brown- 

 colored pyrites, in very minute quantity, is diffused through the stone, and especially is it visible in contact with the 

 sulphuret of chromium. A peculiar blue mineral (iodolite) and a honey-yellow one (apatoid), aa well as traces of 

 sulphur, are likewise present in traces in the stone. 



Wherever the stone is broken or rubbed, it emits the odor of sulphurous acid. Water dissolves from it decided 

 traces of hyposulphate of soda, hyposulphate of magnesia, sulphate of magnesia, chloride of magnesium, chloride of 

 sodium, and silicic acid. 



The proportions in which the different visible minerals are present may be thus expressed: 



Chladnite 90 



Anorthite 6 



Nickel-iron 2 



Magnetic pyrites 



Schreibersfte 2 



Sulphur 



Iodolite and apatoid . . 

 The above minerals have been described mineralogically in my previous report. It only remains to state the 



results obtained in the analysis of the chladnite. They are the following: 



Ratio of 

 Oxygen. oxygen. 



Silicic acid 70.41 35.205 3 



Magnesia 28.25 11.300 1 



Soda 1.39 .338 



100.00 



It consists, therefore, of 11 J atoms tersilicate of magnesia + J of an atom of tersilicate of soda. 

 In operating upon the mixed powder of the stone, lime, alumina, and phosphoric acid were detected, ingredients 

 which are supposed to have reference to anorthite and apatite. 



Three years later von Waltershausen 3 gave an account of an analysis of a small portion 

 of the meteorite as follows: , 



In connection with various investigations concerning feldspar, with which I have occupied myself recently, I 

 became interested in the determination of the composition of a meteoric mass which fell at Bishopville, South Carolina, 

 in March, 1843, from a small fragment of 10 to 20 mm. in length which was presented by Professor Shepard to Mr. Clark, 

 a student of chemistry. 



Some of these fragments possess a glaze peculiar to these formations of about 0.3 mm. in thickness and of a brighter 

 color than is usually seen. The principal part of the stone is composed of a white mineral, rich in silica and of fine 

 crystalline structure, in which are scattered here and there specks and grains of a metallic luster consisting of mag- 

 netic pyrites and brown oxide of iron, which presumably was formed from the pyrites. The hardness of this white 

 mineral, sometimes of a slightly silken luster, is 6. The specific gravity is 3.039. 

 The analysis gave the following result: 



Silicic acid 67. 140 



Magnesia 27. 115 



Calcareous earth 1. 818 



Alumina , 1. 478 



Iron oxide t 1. 706 



Water 0. 671 



Manganese trace 



99. 928 



A glance at the analysis suffices to show that we have no feldspar to deal with here. In order, however, the better 

 to determine the true composition of this mineral, the iron oxide was treated as a foreign body evidently added to 

 the compound, and the analysis then reduced to 100, with the following atomic weights: 



Silica 566, 820 Pelouze. 



Magnesia 250, 500 Scheerer. 



Calcareous earth 351, 651 Berzelius. 



Alumina 641, 800 Do. 



Water 112, 480 Do. 



the composition then "is: Oxygen. 



Silica 68. 356 36. 180 



Magnesia 27. 606 11. 020 



Calcareous earth 1. 851 0. 526 



Alumina 1. 504 0. 703 



Water 0.683 0.607 



100. 000 



