352 Discovery of Yttro-Cerite in Massachusetts. 



tunately, however, the label is lost ; and my memory does not 

 serve me to recall the locality, except that I have an impression 

 that it was found in Worcester County, and the specimen corres- 

 ponds with some of the rock there. I notice also in it fragments 

 of pyrope, which occurs in that county. I have an indistinct 

 recollection of throwing it aside as a poor specimen of purple 

 fluate of lime ; not being then familiar with the yttro-cerite. I 

 place the specimen from Massachusetts and one from Sweden 

 on the table, that the members of the Association may compare 

 them. 



I have made a few chemical trials to ascertain whether this 

 mineral contains hydrofluoric acid, cerium, and yttria, and now 

 give the results. 



The powder was moistened with concentrated sulphuric acid 

 in a platinum crucible, covered with a glass plate, and subjected 

 to a moderate heat, when the glass was decidedly corroded by 

 the hydrofluoric acid. 



Before the common blowpipe the mineral melted into a dark 

 greenish glass, without decrepitation. With borax, its powder 

 formed an orange yellow bead when hot, which, on cooling, lost 

 nearly all its color, passing through one or two shades of yellow- 

 ish green. 



In nitric and hydrochloric acid, the mineral was more or less 

 soluble by long digestion and the application of heat. A solu- 

 tion in nitro-muriatic acid exhibited the following effects with 

 reagents. 



Potassa gave a white abundant precipitate, insoluble in excess. 



Carbonate of potassa gave a white abundant precipitate, slightly 

 soluble in excess. 



Bicarbonate of potassa gave a similar precipitate, slightly solu- 

 ble in excess. 



Ammonia gave a white abundant precipitate, soluble in excess. 



Carbonate of ammonia gave a like precipitate, nearly all solu- 

 ble in excess. 



Red prussiate of potassa gave a yellow abundant precipitate, 

 insoluble in hydrochloric or nitric acid. 



Yellow prussiate of potassa gave an abundant blue precipitate, 

 insoluble in hydrochloric and nitric acid. 



Hydrosulphate of ammonia gave a gray precipitate, which be- 

 came darker on standing. 



