78 < ANALYSIS OF CHROJtATE OF JRON. 



Wy a modifica- It possesses all its properties, and in addition that of cona- 

 tion of it. bining with glue. 



General con Thus it follows, 1, That the saponaceous principle, which 

 elusions. j ias b een S ;,' ic i t have been found in several vegetables* does 



not exist: it is nothing but extract. 



2, That extract has the property of reddening the blue 

 colour of litmus. 



3, That this substance is soluble only in water and di- 

 luted alc< hoi ; neither pure alcohol nor ether having any 

 action on it when well dried. 



4, That when it is diluted with a great deal of water, if 

 it be boiled m contact with air it absorbs oxigen, and falls 

 down in a powder insoluble both in water and in alcohol. 



XIII. 



An Examination of the Chromate of Iron of the Uralian 

 Mountains, in Siberia : by Mr. Laugier*. 



JlNtheyear7 Mr. Pontier discovered in the department 

 Cjuomateof of the Var, near the mansion house of la Cassade, a mineral, 

 iron found in ^jV Ml% Tas&aert first asce ,taiaed to be a compound of 

 r ranee, ... . 



chromic acid, and oxide of iron. Mr. Vauquelin confirmed 



this analysis; and beside a difference in the proportions 



announced the presence of alumine and silex. 



. . „.. . Mr. Meder has since found in Siberia, in the Uralian 

 and in Siberia. . 



Mountains, a substance much resembling the mineral of 



the Var. The examination of this substance, a specimen 

 of which was presented to the author by Mr. Steinacher, 

 of the Society of Apothecaries at Paris, is the subject of 

 the present paper, in which the results of the author's ana- 

 lysis are compared with those of Mr. Vauquelin. 



Though the Siberian mineral pretty closely resembles in 



Comparison of appearance that from the Var, there is reason to conjecture, 



on examining it with attention, that the metal in it is more 



pure: its fracture, instead of being granular, is foliated; 



its metallic lustre is more vivid; and in general it is less 



* Ann. de Chim- vol. LXXVIII, p. 70. Abridged from the Ann. du 

 Museum d'Hist. Nut. vol. VI, p. 325, 



mixed 



