246 Chemical Olscrvations upon Spathic Iron. 



deduces from them, do not appear to me to be so exact ; in as 

 far as he asserts that the calcined ore was attracted by the 

 magnet, that it was dissolved in nitric acid with facility, 

 arid, according to his account, with a very lively effer- 

 vescence ; and that it reduced minium, and, lastly, served to 

 decompose cinnabar : he concluded from all these circum- 

 stances,, that the iron in this ore was in the true metallic 

 state. This inference is obviously so inadmissible that we 

 need not dwell upon it. 



The Following experiment deserves to be described. Af- 

 ter having treated ihe ore with nitric acid and evaporated it 

 to dryness, he washed the residue, and obtained from the 

 liquor by means of fixed alkali a white earth, which he says 

 he found after repeated experiments to be calcareous earth. 

 We shall soon see the reasons which I have for doubting 

 the accuracy of these experiments, as well as his discovery 

 of zinc in a remarkable quantity in this ore. The small 

 black flakes which he perceived in the muriatic acid which 

 had been poured upon this ore, made ,him think that this 

 metal existed there. To convince himself of it, he digested 

 in the cold for ten or twelve days some sulphate of iron dis- 

 solved in a small quantity of water, upon spathic iron cal- 

 cined and wdl pulverized, taking care to agitate the mixture 

 from time to time; he afterwards filtered it, and obtained 

 by evaporation, and allowing it to subside, crystals, which 

 appeared to him to be sulphate of zinc. 



This result is without doubt very remarkable. M. Dize 

 also judged it necessary to verify this fact upon the same 

 specimen which Bayen made use of in his experiments. 

 M. Dize, in order to obtain oxide of zinc, employed the ac- 

 tion of nitric' acid and precisely the same kind of evapora- 

 tion which Bayen made use of to extract this calcareous 

 earth, which he had ascertained, as he says, by decisive ex- 

 periments. Tin experiment of M. Dize was made upon 

 fiflv grammes : he obtained by means of a fixed alkali five 

 grammes of a white substance of an earthy appearance, 

 which be mixed with double its weight of charcoal, and di- 

 stilled in an .earthen retort. Upon the apparatus cooling, 

 particles of zinc were found sublimed at the top of the retort. 



This 



