4S2 Dr. Schafhaeutl- on the Different Species of 
Its weight was found to be 0*75 grains, and it had therefore 
lost in the acid 2-64 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 trace 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 
Silicon. . . 0*1595 or silica 0*3320 
0*3814 0*6520 
The hydrochloric solution, from which the white powder just 
mentioned remained, w^as colourless as water ; after oxidation 
with nitric acid, oxide of iron was separated 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 protoxide 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 the 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 lotal amount 0*939550 
Silicon 0*127306 
Do. mixed with the residuum 0*025000 
0*152306 
