402 Dr. Andrews on the Heat developed during the Formation of the 



22. Iodide of zinc and water, Zn I -|- Aq. 



Th. air 



T' 



J. • • • • • • 



rpf 

 X ■ • • • • • 



Inc. c 



Aq 



Sn. (sp. heat 0.56) 



Vss 



Zn I 



Heat of comb. . . 



58°.60 . 



58°.02 . 



59°.07 . 



1°.02 . 



159.1 gm. 



4.8 . 



19.1 . 



3.52 . 



66°.5 . 



59M0 . 



59°. 12 . 



60°.21 . 



r.06 . 



159.6 gm. 



5.0 . 



19.6 . 



3.92 . 



62°.6 . 



Mean heat referred to iodine as unit, 62°.8. 

 Mean heat referred to zinc as unit, 246°. 



38°.4 



37°.58 



40°.12 



2°.52 

 125.6 gm. 



10.7 



21.6 



8.42 

 59°.3 



COMPOUNDS OF IRON. 



23. Iron and chlorine, Fe^ + CI3 + Aq + Fe. 



24. It must be carefully observed that the unit here taken is not the whole of 

 the iron dissolved, as in the case of zinc, but only two-thirds of it ; because the 

 remaining third does not enter directly into combination with the chlorine, as has 

 been already explained. 



