1885.] NEW-YORK MICROSCOPICAL SOCIETY. 157 



Condenser. It can be readily adapted to the substage of any 

 microscope. The mounting is simple and light. The diaphragm- 

 plate is easily manipulated. , 



Meeting of May 15TH, 1885. 



The President, Mr. C. Van Brunt, in the chair. 

 Thirty-seven persons present. 



OBJECTS EXHIBITED. 



1. Syenite from the Obelisk, Central Park ; shown by polar- 

 ized light : by A. Woodward. 



2. Foraminifera from Raine Island — one hundred and fifty 

 forms, representing one hundred species, gathered from a depth 

 of one hundred and fifty-five fathoms; prepared by Mr. Joseph 

 Wright, of Belfast, Ireland : by A. Woodward. 



3. Crystals containing cavities with Inclusions : by A. A. 

 JuLiEN. Among these were, — 



(i) Topaz, granyte, and smoky quartz, showing cavities con- 

 taining liquid carbonic acid gas and a bubble of the gas. 



(2) Crystal of topaz, showing cavity containing brine with 

 crystals of sodium chloride. 



(3) Quartz with large cavity containing a movable globule of 

 water. 



(4) Artificially prepared crystals of sodium chloride clouded 

 by cavities filled with solution of potassium dichromate. 



4. Photographs, in different planes, of Triceratium Davy- 

 anum : by P. H. Dudley. 



INCLUSIONS IN CRYSTAL. 



Dr. A. A. Julien read a Paper entitled " The Sealed Flasks 

 of Crystal." He treated particularly the inclusions found in 

 smoky quartz. His Paper constitutes the first article in this 

 Number of the Journal. 



PHOTOGRAPHS OF TRICERATIUM DAVYANUM. 



Mr. P. H. Dudley exhibited and described three photographs 

 of Triceratium Davyaniim which, by representing the diatom as 

 it appears when viewed in as many different focal planes, eluci- 

 date, in part, its sculpture. His description forms the second 

 article in this Number of the Journal. 



