Atomic Volume of some Minerals. 237 
3. White Iron i 
28 — of elements, 3. 
1 Fe er A. 750-476 (sp. de =157- 
a, At. weight, 750 C. 15756+3=5 2°52 
The atomic volumes of these minerals are, 
If As isa single atom, 89°24 66°6 52°52 
If As is a double atom, 59°49 555 52°52 
These species have each arhombic form; but as Prof. G. Rose 
has observed, they appear to differ too wide ely to be considered 
isomorphous. The angles M: M are respectively 122926’, 111953’ 
and 10630’. This chemist also remarks that the elements arsenic 
and sulphur are very different in crystallization, and therefore we 
have no good authority for assuming them to be isomorphous. If 
we admit As to be a single atom the atomic volumes are widely 
different ; but if a double atom, they approximate rather closely. 
n this connection, the atomic volume of olivenite (with which 
Libethenite is isomorphous) may be stated. ‘The rhombic prism 
has M:M ( «P)=109°10/, Pc=84°45’; while in white iron 
pyrites cP = 106°30/and P «=81°50’, in Mispickel «P= 111953’ 
and P o; = 80°89’ ; 
1. Olivenite. 
§ As meee 06 6. atoms of — and bases, 6. ¢. atoms o f el its, 16. 
4 31 A. oraepe o, w= 14 
4 Ou ate B. 822° eae aes 2°74—~-16==5 1°42 
1 112-48 [If As is a double atom, then seutt and C==48'4.] 
a. At. volume, 3402°04 
2. Libethenite. 
1 = 8923 6. atoms of acid and bases, 6. c. atoms of elements, 16. 
4Cu 1986-4 A. 2991 gists (sp. gr.) =808'4 
1H 11248 B, 808:48+-6==134°7 CO. 808:48+16=50°53 
a. At. volume, 2991-18 
XXIL Nitrate of ee ee of Manganese—Carbonate of Zine—Light 
Reed Silver Ore. (see p 
1. Nitrate of Soda, 8. R: R=106° 33’, 
Na = 3909 5. atoms of sneein nd base, 2. ¢. atoms of elements, 8. 
1N 675-06 A. 1065-96-21 (sp. gr.) =507°6 
@ At. weight, 106596 B. 507-6+-2==253'8 C. 507-6--8=68-45 
2. Carbonate of a Mn G; R:R=106°51’. 
1 Mn = 4447 8, atoms S ree and base, a ec. atoms of elements, 5. 
16 oe 9°1--8-599==' 
a. At. weight, 7197  B, 2004+2=100°2 C. 200°4—+-5==40'1 
8. Carbonate of Zine, Zin G, R: R=107°40’. 
Mm = 5066 6, atoms of acid and base, 2. ¢. atoms of elements, 5. 
16 275° A. 781°6+-4°4 (sp. gr.) =177°6 
4. At. weight, 7816 B, 177°6--2==88°8 C. 1776+5=35°5 
