98 Dr. Steeg & Reuter, Homburg. 



Calcite Preparations: Nicol's Prisms, amongst these one of 

 abnormal size, an unique specimen, 40 mm (1 2 /V) across the face; various 

 polarizing prisms a la Foucoult, Grlan, Hartnack, Jellet-Cornu; double 

 refracting prism. 



Three large rhomboeders with various surfaces. 



Quartz Preparations: Large prisms and lenses on brass stands. 



A tube of nickel-plated brass with quartz lenses for spectroscopic 

 examinations with Soret's movable ocular and uranium glass disc, double 

 refracting prism and tube for liquids. Babinet's compensator in brass mount. 



Quartz wedges, double disc, Bertrand's quadruple plate, double 

 refracting prisms and Fresnel's triple prism; a large sphere. 



Selenite Preparations: Various wedges, concave discs, various 

 Selenite figures. 



A collection of 16 unannealed glasses, in case. 



Interference Apparatus: Fresnel's Mirror Apparatus, on brass stand. 

 Interference prism, Billet's lens, cylindrical lens, all on brass stands. 

 Newton's coloured rings, in brass mount. 



Fluorescence: Four cubes of uranium -didym-saphirin glass and 

 fluor-spar, in case. 



Perforated case with 5 fluorescent liquids. 



