Mineral Synthesis. 



the vessel according to the diverse 

 conditions of temperature. When the 

 solution was evaporated at ordinary tem- 

 perature, the walls of the vessel and the 

 surface of the liquid were covered with 

 a crust of calcite crystals, while the bot- 

 tom was coated with a granular layer of 

 calcite. If the solution be evaporated at 

 a low temperature in a vessel largely 

 covered; the surface of the liquid is 

 covered with crystals of aragonite while 

 the bottom is coated with calcite rhom- 

 bohedra. 



Dolomite was formed by Morlot, in 

 1847, by heating a solution of sulphate of 

 magnesia in a closed tube at 200 degrees. 

 Durocher heated to redness in a sealed 

 gun barrel fragments of porous limestone 

 and magnesium chloride. This temper- 

 ature was kept for three hours, when 

 the pieces of limestone were covered with 

 a scoriaceous coat which was treated 

 with boiling water. The microscope 

 disclosed an aggregation of grains of 

 crystalline dolomite. From this experi 

 ment Durocher concluded that dolomite 

 was formed in nature by the action of a 

 solution of magnesium salt on calcium 

 carbonate under slightly increased tem- 

 perature and pressure. 



Most of the minerals employed in 

 the arts and industries have been repro- 

 duced. Galena was often noted as 

 an accidental product and nearly always 

 with cubic form. Senarmont, in 1851, 

 formed galena crystals by a method which 

 now is commonly used in the formation 

 of most metallic sulphides. He placed 

 in a glass tube with thick walls the 



r 



1 







1 



1 1 





1 



2> 



> 



2^ 



j 



FIGURE I. 



Artificial Minerals, 



(After Doelter.) 



H — R utile, e — Olivine. 



b — Argent ite. X—Augite. 



— Leucite g — Anorthite. 

 d — Xeph el in e . 



