Chemical Observations upon Spathic Iro'ti. 249 



composition. The remainder is water and carbonic acid. 

 It is worthy of remark, that the proportion of iron is deter- 

 mined according to those of the other principles, all of 

 which were examined with care, by deducting their amount 

 from the quantity of ore submitted to analysis. Conse- 

 quently the losses made upon these principles would corre- 

 spond to the augmentation of the proportion of the iron j 

 we must therefore suppose, that this proportion is a little too 

 high in the result of this analysis. 



M. Bucholz searched for the manganese particularly, but 

 he did not discover an appreciable quantity of it : besides, he 

 employed so many different methods, in order to ascertain 

 that this ore contained no other substance, either carthv or 

 metallic, that we cannot accuse his results of error. 



M. Bucholz also observed, that in the calcination of this 

 ore, the carbonic acid is in part decomposed ; and that a ga3 

 is evolved which burns blue, and which he designates by the 

 name of gaseous oxide of carbon. 



Lastly, M.Drappier, in a memoir lately published*, has 

 announced, that the specimens of spathic iron which he ex- 

 amined did not contain any lime ; that they contained only 

 a very small quantity of manganese ; but that he found mag- 

 nesia in a very great proportion. Before proceeding any 

 further, I shall mention two analyses of M. Bergman, re- 

 lated by M. Hassenfratz in a note printed in the same paper. 

 As the latter had it principally in view to make known the 

 quantity of lime contained in spathic iron, and as the pro- 

 portions obtained from the two specimens have been very 

 different, we may again conclude that this substance is fo- 

 reign to spathic iron. VVc may draw the same consequence 

 from a third analysis reported in the same note, and «#hich 

 appeared to have been made upon a specimen of roasted 

 ore, although water is mentioned in it. This is certainly 

 occasioned by some mistake of the press or of the editor. 



The little conformity between the analyses of Bergman 

 and those of Bucholz and Drnppier ; the existence of the 

 oxide of manganese in great proportion, annoimced in such 



• For a translation of M. Drappicr's paper, sre p. CI of the present vo- 

 lume. 



a positive 



