>]2 REPORT 1860. 



Specific gravity 2*604. 



Silica 3471 



Alumina 17*1 8 



Magnesia 3656 



Water 11*49 9994 



Connemara Garnet. — Occurs in rhombic dodecahedrons with bevelled edges; faces 

 of crystals have a metallic lustre, colour resembling bronze. The matrix appears to 

 consist of the same mineral mixed with epidote. 



Specific gravity 3-585. 



Silica 39-77 



Alumina 15-49 



Sesquioxide of iron 16-27 



Lime 25-98 



Magnesia 2 - 06 



Manganese -48 10005 



Analysis of the Matrix. 

 Specific gravity 3'404. 



Silica. 39-27 



Alumina 1821 



Sesquioxide of iron '. 15*1 1 



Lime 23-45 



Magnesia 3*17 



Traces of manganese ,, 99-21 



On the Composition of Jet. By Thomas H. Rowney, Ph.D., F.C.S., 

 Prof, of Chemistry, Queens College, Galway. 



The following results were obtained by the analysis of two specimens of jet and of 

 a very pure coal, a portion of a fossil plant : — 



Jet No. 1. Jet No. 2. Coal. 



Specific gravity 1-2655 Specific gravity 1-1743 1-2860 



Coke 4119 27-38 .... 71-65 



Volatile matter . . 58-81 72-62 28-35 



100-00 



Carbon 78-60 , 



Hydrogen 6-21 



Nitrogen 1 '27 



Sulphurand \ n . 17 



Oxygen J 



Ash 2-75 



100-00 10000 100-00 



On Waterproof and Unalterable Small-arm Cartridges. By T. Scoffern. 



On a New Form of Blowpipe for Laboratory Use. 

 By Dr. Hermann Sprengel. 



Mr. Svmons exhibited some forms of Alkalimeters suggested by Mr. Wiers. 



On Thiotherine, a Sulphuretted Product of Decomposition of Albuminous 

 Substances. By Dr. Thudichum. 



