318 PROCEEDINGS OF THE ACADEMY OF 



August 5. 

 The President, Dr. Ruschenberoer, in t.he chair. 

 Ten members present. 



August 12. 

 The President, Dr. Pusciienberger, in the chair. 

 Six members present. 



August 19. 

 The President, Dr. Rusciienberger, in the chair. 

 Fourteen members present. 

 Tlie death of Elias Durand and Dr. L. S. Belles was announced. 



The Composition of Traidwinile. By E. Goldsmith. — The 

 very small quantity of the substance I had for the first examina- 

 tion of the above-named mineral (see Proceedings of the Academy, 

 Jan. 1, 18Yo) caused me to overlook a few important elements, 

 namely, silica and lime. 



John C. Trautwine, to whom my thanks are due for procuring 

 more of the substance, has ascertained that the locality of it is 

 Monterey County, California. The mechanical separation of the 

 Trautwinite from the chromite is a difficult and tedious ope- 

 ration ; however, I succeeded so far, that with the lens no black 

 particles of chromite could be discerned. 



As the substance is insoluble in acids, I brought it into the 

 soluble condition by fusing it in a mixture of carbonate of soda 

 and saltpetre, treating the fused mass with water until all the 

 soluble parts were exhausted, and the insoluble part with hydro- 

 chloric acid. . What the acid had not dissolved was again fused 

 with soda and saltpetre, and the obtained mass treated the same 

 as before. From the alkaline solution, after acidulation and re- 

 ducing the chromic acid to sesquichloride of chromium by hydro- 

 chloric acid and alcohol, I separated first silica, then the sesqui- 

 oxide of chromium. 



The other solution, containing the bases as chlorides, was 

 evaporated to dryness, moistened with hydrochloric acid, water 

 added, and thus I found another small quantity of silica. The 

 alumina and iron were then separated from the lime and magnesia 

 by ammonia; but the iron and alumina were again dissolved and 



