On Trihasic Phosphoric Acid. 17'.' 



by its own oxydatiOn and reduction, the complicated car- 

 boniferous compounds with which nature and human fore- 

 sight supply the soil, into more simple forms that alone are 

 adapted to the maintenance of vegetable life; and after having 

 converted them into those compounds, retains them and dis- 

 poses of them to the plants under the influence of the Btronger 

 living power of assimilation by means perhaps of the water of 

 hydration, which is always, even after the long-continued heat 

 of a hot summer, to be found in sesqnio.xide of iron, and 

 which, if I may say so, serves as a channel of transportation of 

 the inflexible, motionless, dead mineral into the living plant 

 and animal. 



This tendency of the sesquioxide of iron to retain alkalies 

 seemed to me as bearing a part in the formation of compounds 

 like TtO, Fe 2 3 . I therefore tried to produce a compound in 

 which the protoxide would be an alkali. To this end, I heated 

 a certain quantity of iron alum with carbonate of potassa for 

 over six hours in a porcelain crucible, which was inserted into 

 an ordinary Hessian crucible, at the strongest white heat I 

 could produce. After washing with water, I separated, as far 

 as I could, the black, heavy crystalline part from the red 

 deposit which after awhile was forming, (living my experi- 

 ence, I must say that the black undecomposed substance was 

 KO, Fe 2 3 , which, by boiling with water, was decomposed, the 

 potassa becoming eliminated, and the iron converted into a 

 sandy red hydrate. The black powder, as I obtained it, was 

 after drying at 100° C. a little magnetic, dissolved to a beauti- 

 ful red color in hydrochloric acid, was free from Bulphuric 

 and carbonic acids, and was composed of 



To. si 1 Fe 2 3 

 14-.00 K<> 

 15.20 IK) 



Part of it was here already decomposed, which may per- 

 haps be illustrated in the following way: 



