1893.] Mineralogy and Petrography. 1009 
over Court House, Virginia. Analyses follow (I, black soil; II, glau- 
conite) : 
Sand SiO, TiO, ALO, FeO, CaO MgO SO, CO, P.O, KO Org. HO 
1.59.82 545 64 7.14 400 61 A1 —98- AT 139 191 1249 686 
Quartz SiO, AlO, FeO, FeO CaO M gO KO NaO HO Total 
Il 2.76 47.45 7.33 12.3 943 57 .2.90..5.75 .:.42 9.85 — 98.49 
8.22 43.34 6.62 15.16 8.33 .62 95 415 1.84 10.82 — 99.55 
Schwartz has treated in a comprehensive essay” the history of the 
observations on reciprocal changes produced in polymorphous bodies 
under different conditions of temperature, and has, in addition, given 
the results of some independent observations of his own. The substan- 
ces that have been experimented upon are: Agl, KNO,, NH,, NO,, 
AgNO, Rb (NO,), boracite, perchlorethane, tetrabrommethane, and 
copper, nickel, zine and cobalt, sodium-urany] acetates. 
Ch. Friedell? has examined carefully a specimen of the meteoric iron 
from Cañon Diablo, Arizona, and, as a result of his study, has con- 
cluded that: particles of black diamond (carbonado) are disseminated 
through its mass. A combustion of the residue obtained upon treat- 
ment of the iron by acids leaves no doubt but that the material con- 
sists principally of carbon. 
? Gekronte Preisschr. Univ. Goétinger, 1892. 
% Bull. Soc. Franc. d. Min., XV, p. 258. 
