348 PROCEEDINGS OF THE ACADEMY OF 



August 5. 

 The President, Dr. Ruschenberger, in the chair. 

 Ten members present. 



August 12. 

 The President, Dr. Ruschenberger, in the chair. 

 Six members present. 



August 19. 

 The President, Dr. Ruschenberger, in the chair. 

 Fourteen members present. 

 The death of Elias Durand and Dr. L. S. Bolles was announced. 



The Composition of Trautwinile. B}- E. Goldsmith. The 

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

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

 Jan. 1, 1873) 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 Count}'', 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 tiie 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 tlie 

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

 chloric acid. AVliat 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 aeidulation and re- 

 ducing the chromic acid to sesquichloride of chromium by hydro- 

 cliloric 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 hj'drochloric acid, water 

 added, and tlius 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 



