Metallic Compounds of Chlorine, Bromine, and Iodine. 



403 



25. Iron and bromine, Ye^ + Brj -\- Aq -|- Fe. 



49°.00 

 47°.52 

 53°.55 

 6°.14 

 147.4 gm. 

 2.7 

 19.4 

 1.145 

 909° 



26. 



Mean heat referred to bromine as unit, 909°. 

 Mean heat referred to iron in Fe2 as unit, 3933° 



Iron and iodine, Fe^ + 13+ Aq -\- Fe. 



Th. air. 

 T' 



rpf 



X • • • • 



Inc. c. . . 

 Aq. . . 



Sn. (sp. heat 

 Vss. . . 

 I. . . . 

 Heat of comb 



63°.40 

 61°.04 

 65°.99 

 4°.97 

 157.7 gm. 

 54) . 4.2 

 19.6 

 2.752 

 327°.8 



Mean heat referred to iodine as unit, 329°.2. 



Mean heat referred to iron in Fe2 as unit, 2299°. 

 27- The object of the experiments detailed in the three following tables was 

 to determine the heat evolved, when solutions of the sesquichloride, sesqui- 

 bromide, and sesquiiodide of iron are converted into solutions of the proto- 

 compounds by agitation with an excess of iron. The sesquichloride of iron, 

 obtained by the action of dry chlorine gas upon heated iron, was dissolved in 

 water (the quantity being adjusted as usual) in the glass vessel, and an excess of 

 iron filings was placed in one of the small balls. But I was obliged to have re- 

 course to a different method in order to procure determinate quantities of the 

 sesquibromide and sesquiiodide of iron in solution, from finding it impossible to 



3f2 



