H. L. Wells — Bismutosphcerite from Connecticut. 273 



bismuthinite are a trace of iron and in some parts a very small 

 quantity of insoluble silicates. The remarkable uniformity in 

 the composition of separate portions, as shown by the analyses 

 which follow, is a strong argument in favor of homogeneity. 



Mr. E. S. Sperry of this laboratory has made the following 

 analyses of two separate portions. 



A. B. 







i. 



ii. 



in. 



Bi o by ignition, 



92-07 



92-05 



92-04 



92-07 



co 2 



8-01 



7-90 



7-96 



7-91 



H 2 



0-90 



0-48 



0-66 



0-49 





100-98 



100-43 



100-66 



100-47 



Bi 2 3 by determina- ) 









91-09 



The above analyses and those that follow were made by ig- 

 niting the substance in a boat in a combustion-tube through 

 which dry air was passed. More than 1 gram of substance was 

 used for each analysis. The H 2 and C0 2 were collected and 

 weighed as in organic analysis, while the residue in the boat 

 gave the " Bi 2 3 by ignition." In one case, B III, this residue 

 was dissolved and BiOCl was weighed on a Gooch filter. In 

 these analyses the small amount of Bi 2 S 3 present was disre- 

 garded, but Mr. Sperry made a determination of the residue 

 insoluble in dilute HC1 by collecting it on a Gooch filter, dry- 

 ing at 100° and weighing. He found: 



B. 



IV. 



Black residue 0'56 per cent. 



Mr. Sperry's analyses showed such uniformity in the two 

 portions examined that I was led to make a somewhat more de- 

 tailed analysis of a third sample. My results were as follows : 



C. 



I. Calculated for Bi 2 00 6 



Bi 2 3 



91-64*] 



Q '^t )■ 92-06 ignited residue, 

 es 0-08 j & 



91-41 



S0 3 



Insoluble silicat 





Fe 2 3 



trace j 





C0 2 



8-03 



8-59 



HP 



0-47 







100-56 



100-00 



Deduct 0,f 



•28 





100-28 



* By difference ; i. e., the ignited residue minus the S0 3 and insoluble silicates. 

 f It is assumed that the S0 3 contained in the ignited residue resulted from the oxi- 

 dation of Bi 2 S 3 ; therefore 4 atoms of oxygen are deducted for each atom of sulphur. 

 Am. Joub. Scl— Third Series, Vot,. XXXIV, No. 202.— Oct., 1887. 

 18 



