Intelligence and Miscellanies. 185 



was found in the native iron of Canaan. They weighed 0.2 

 grs. and from other trials, appear to exist in the mineral pret- 

 ty constantly in this proportion. The nitric solution was 

 precipitated by ammonia, and the residuum after drying in- 

 dicated 48.7 grs. of metallic iron. 



I afterwards repeated my examination with greater care in 

 the following manner. Twenty five grs. were dissolved in di- 

 lute nitric acid. This solution was boiled for some time with an 

 excess of soda, and deposited 35 grs. of the peroxide of iron. 

 The supernatant liquor with the washings of the precipitate 

 being evaporated and neutralized by nitric acid, was de- 

 composed by nitrate of lead, and afforded a precipitate 

 weighing 1.5 grs. which, upon burning charcoal gave the 

 smell of arsenic, and was entirely soluble iri nitric acid, and 

 therefore consisted wholly of arseniate of lead. The result 

 of my trial, then, would be as follows, after deducting the 

 weight of the plumbago — for 24.9 of the mineral. 



Iron, 24.263 



Arsenic, .... 389 



24.652 

 Loss, ■ 248 



24.9 



Which gives per hundred of the mineral, free from the 

 plumbago. 



Iron, 97.44 



Arsenic, 1.56 



99 

 Loss, 1 



100 



This therefore cannot but be regarded as a singular sub- 

 stance, especially as it affords us an instance of the remark- 

 able effect produced by a small proportion of arsenic in dis- 

 guising the natural properties of iron. Whether it coincides 

 with the species described by Mohs under the name of axot- 

 omous arsenical pyrites, (to which opinion I am rather in- 

 clined from its crystalline character and specific gravity,} or 



Vol. XIV.— No. 1. 24 JJ 



