PROCEEDINGS OF SOCIETIES. 213 



microscope (1-iuch objective), thevolatilization of cyanide of mercury 

 from the ordinary glass slide into the thin glass cover (a method 

 which Mr. Hendry also employs for arsenic, &c.), and the notel 

 exhibition of hexagonal crystals, derived by the spontaneous 

 evaporation of the blood-red compound of sulpho-cyanide of iron, 

 arrested at a givea period. 



Mr. Ball of Brigg, read an article on the tougues of the Gaste- 

 ropoda, illustrated bynumerouse home-mounted slides of consider- 

 able interest, value, and beauty. The position and general structure 

 of the " so-called tongue," was demonstrated from an examination 

 of the common snail; the different purposes it serves, and its utility 

 in classification, were duly treated upon ; also the method employed 

 in the preparation and mounting, &c. &c. 



The papers also of IMr. Harrison on Acari ; Mr. Sleigbt, Dr. 

 M'Millan, and others, contributed largely to the interest of the 

 session ; and during the summer months several rural excursions 

 were in contemplation. 



The Miceoscopical Society of JS'ewcastle-on-Ttne. 



This Society, which was established at the conclusion of a 

 series of meetings connected with a microscopical class formed 

 for mutual improvement, entered upon its third year in February 

 last. During the past year, meetings either out-door or in-door 

 have been held fortnightly, and various interesting papers have 

 been read, and addresses delivered; the out-door meetings 

 consisted of excursions to the sea-side and the country, on which 

 occasions the members, provided with requisites for making 

 microsc':^pic gatherings, obtained such objects of interest as the 

 various localities afforded. 



At its regular in-door meetings, besides practical discussions on 

 various subjects connected with the microscope and the exhibition 

 of many valuable microscopic objects, the following papers were 

 read by the members : 



Mr.John Brown, " On the Structure of the Microscope and the. 

 modes of using its various Appliances." 



Mr. T. P. Barkas, " On Objects of Microscopic Intsrest to be 

 found on the Sea-coast." 



Dr. Donkin, " On the Binociilar Microscope." 



Mr. B. Proctor, " On Binocular Vision, and the Binocular 

 Microscope." 



Mr. John Martin, " On how to make a Binocular Microscope." 



Mt. B. Proctor, " On the Advantages and Defects of the 

 Binocular Microscope." 



Mr. John Brown, " On Petals of Plowers." 



Mr. T. P. Barkas, " On Fresh-water and Marine Aquaria, 

 and their Microscopic Inhabitants." 



Mr. John Brown, " On Aphides." 



