1892.] NEW-YORK MICROSCOPICAL SOCIETY. 5~ 



ture of 1,500° C, the influence of the humid air always caused 

 the formation of the rubies and the separation of the hydrofluoric 

 acid. And at the close of their studies on the Synthesis of the 

 Ruby they announce that rubies can be made in two different 

 ways: by the decomposition of the alkaline aluminate by the influ- 

 ence of hydrofluoric acid, or by merely heating the fluoride of 

 aluminum to a temperature equal to that of its disintegration. 



•" The illustrations which I exhibit this evening I have taken 

 from 'The Synthesis of the Ruby,' by E. Fremy, 1891,410, page 

 58, plate 21, published by Vve, Ch. Dunod, Paris. Some of the 

 largest rubies figured on these plates have been magnified sixty 

 diameters, hence their true diameter is from one to two millimetres — 

 one-twenty-fifth to one-twelfth of an inch. M. Fremy did not 

 succeed in obtaining crystals weighing more than fifty-five milli- 

 grammes — one-fourth of a carat — each, before cutting, and the 

 rubies, in the jewelry figured on these plates, were natural crys- 

 tals, not cut gems. Up to the present time he has not produced 

 rubies of sufficient size to warrant their sale in the gem markets. 



" Prof. Dr. Anton Fritsch, Director of the Royal Geological 

 Survey of Bohemia, has prepared, in all, two series, by the gal- 

 vanoplastic process, of reproductions of the Permian reptiles of 

 Bohemia. Many of these are exceedingly small, and the mark- 

 ings of their remains in the rocks are very delicate. The small- 

 est and most interesting of the group is the Seeleya pusilla, which 

 I show this evening under a three-inch objective. The entire 

 reptile measures less than one inch in length. Dr. Fritsch has 

 also restored twelve of the more important reptiles, and has ar- 

 ranged them on a fac-simile of Permian rock. Under a three- 

 inch objective the complete reptile is shown, the dentition being 

 remarkably perfect, as well as all the vertebrae and the feet. A 

 photograph of this I have brought with me this evening, and also 

 one of the isolated reptiles — Ricnadon — of this group. 



" The optician, Ivan Werlein, of Paris, while making some 

 plates of quartz for a new galvanometer, found it necessary to 

 cut these sections parallel to the rhombohedron, making the sec- 

 tions the thinness of less than one-tenth of a millimetre, or one- 

 two-hundredth of an inch, of three inches in length and one-half 

 an inch in width. These plates of quartz were coated on the 

 one side by a thin deposit of silver, the current being measured 



