432 Dr. Schafhaeutl o?i the Differejit Species of 



Its weight was found to be 0'75 grains, and it had therefore 

 lost in the acid Q.'Q^ grains. 



During ignition it emitted very dense fumes — had changed 

 its dark black colour into a dirty reddish-white ; it had lost 

 only 0*051 grains, notwithstanding the great apparent evo- 

 lution of gases, and we must therefore conclude, that the 

 black residuum contained silicon, taking in exchange for 

 carbonaceous matter oxygen from the atmosphere. 



By means of hydrochloric acid and succinate of ammonia 

 iron was separated with a ti'ace of manganese = 0*32 grains 

 = 0*2219 grains of metallic iron, and silica = 0*332 grains 

 = 0*1595 grains of silicon. 

 The oily residuum contained therefore, in 0*6989 grains, 

 Iron .... 0*2219 or peroxide of iron .... 0*3200 



Sihcon. . . 0*1595 or silica 0*3320 



0*3814 0-6520 



The hydrochloric solution, from which the white powder just 

 mentioned remained, was colourless as water ; after oxidation 

 with nitric acid, oxide of iron was sepai'ated equal to 3*12, 

 viz.: iron 2*163408, and oxygen 0*956592; oxide of iron se- 

 parated from the silica = 0*32 grains. The oxide of iron con- 

 tained in the liquid amounted therefore, as we see, to 3*12 gr.; 

 on the contrary, what the iron lost by this treatment with 

 acids amounted only to 2*64; the iron therefore could be 

 neither in the state of pi'otoxide nor peroxide in the remain- 

 der. 



Now the first residuum before ignition weighed 3*13, 

 after ignition 3*55 *, and contained therefore 



Silica 0-265 



Silicon 0-025 



0*290 

 Loss of protoxide of iron . 3*260 



3*550 grains,* 

 which is the weight of the residuum as before mentioned. 



If we now consider ihe amount of iron and oxygen in the 

 first separation of protoxide and peroxide of iron, we find 

 Peroxide: 

 Iron .... 1*7335 Oxygen .... 0*766500 



Protoxide : 

 Iron . . . . 0*5869 Oxygen . . . . 0*173050 



Total amount 2*3204 Total amount 0-939550 



Silicon 0*127306 



Do. mixed with the residuum €-025000 



0*152306 



