386 ' Miscellanies. 



many tons weight, appears to have been twisted round after it was 

 detached from the wall, and now rests on one corner, its upper end 

 leaning against the wall ; the strength of fifty men, unaided by ma- 

 chinery, would not serve to move it from its present position. On 

 parts of the walls are fragments of fresco paintings, the colors of 

 which are still quite fresh. We also visited the convent belonging 

 to the same order, of which all except the lower story is destroyed ; 

 the '^ patio " or courtyard, is surrounded by a very handsome set of 

 ornamented arches built of the same spongy lava of which the town is 

 composed. The church of San Francisco, which was partially de- 

 stroyed in 1800, has been rebuilt, or rather repaired ; evident traces 

 remain in it of the effects of the earthquake. Scarcely a month 

 passes at La Tacunga without the shock of an earthquake. T. 



2. Details of a chemical analysis of Danaite, a new ore of iron 

 and cobalt ; by Augustus A. Hayes. — The ore which was the sub- 

 ject of this analysis, was discovered some years since at Franconia, 

 N. H.* and from its crystallographic and pyrognostic characters, it was 

 considered as a new variety of arsenical cobalt ; but as these would 

 not enable us to determine whether the cobalt was present in an 

 atomic or variable quantity, an analysis was attempted. It was, 

 however, found difficult to effect so complete a separation of the 

 constituents, as to give a true statement of its composition. The 

 specimen examined was in the form of brilliant and perfect crystals, 

 having a specific gravity of 6.214. 



I. A portion which had been crushed in paper, was washed, dried, 

 and reduced to a fine powder in a mortar of porcelain ; the fine pow- 

 der was exposed in warm air, and then cooled in a desiccated atmos- 

 phere. 



II. 1000 parts of the powder were introduced into a flask, hav- 

 ing a curved neck, with 6000 parts of strong muriatic acid. A few 

 drops of nitric acid were added, and the flask connected with a large 

 receiver, containing nitrous acid ; as the action became less active, 

 more nitric acid was added, and heat applied to the flask ; the sul- 

 phurous acid being converted into sulphuric, and the hyposulphurous 

 depositing sulphur in the receiver ; by the cautious addition of nitric 

 acid, the whole of the arsenic was taken up by the muriatic acid, 

 leaving a portion of sulphur undissolved. The fluid was decanted 



* Am. Jour. Vol. Vill, p; 302. 



