88 Intelligence and Miscellaneous Articles. 



metallic fluorides ; but it appears to officiate less powerfully as an 

 acid than fluoride of silicon does. They are all decomposed by 

 prolonged contact with the air. 



The relation between the fluorine of the basic fluoride and that of 

 the fluoride of zirconium is either — 



1 1:4 



II 2:4 



III 3:4 



IV 4:4 



presenting a perfectly regular series, which precludes the possibility 

 of assuming three atoms of fluorine in fluoride of zirconium. 



The most stable of these compounds, as well as the most common, 

 is the second. It may be taken as the type of the normal fluozir- 

 conate, M Fl, Zr Fl 2 . 



There is one crystallized compound which does not belong to the 

 above series. It has the abnormal relation 5 : 8, which leads to the 

 formula 5 Na Fl, 4 Zr Fl 2 . However singular this formula may appear, 

 it is preferable to the more complicated one, 15NaFl, 8Zr 2 Fl 3 , 

 which the old formula of zirconia would require. 



From the constitution of these salts, numerous instances of iso- 

 morphism between them and the fluosilicates, fluotitanate3, and 

 fluostannates might be expected. Such, however, is not the case. 

 There is isomorphism only in the case of the zinc and nickel 

 salts, which cannot be distinguished by their forms from the fluosili- 

 cates, &c. 



The following is a list of the fluozirconates of which the crystal- 

 line forms have been determined. They are arranged in isomor- 

 phous groups : — 



KFl,ZrFl 2 ) *^J\ u -a i ■ 



NH 4 F1 ZrFl 9 I Right rhomboidal prism. 



3KFl,2ZrFlM „ , . , , 



3NH«Fl,2ZrFl 2 j '••• Regular octahedron. 



KF1, 2ZrFl 2 + 2Aql rkkr , ^, . 

 5 Na Fl 4 Zr Fl 2 j ' 0bll( l ue rhomboidal prism . 



MgFl,ZrFl 2 + 5Aq\ tA 



MnFl,ZrFl*+5Aq/ ' ia * 



ZnFl,ZrFl 2 + 6Aql ... 



NiFI,ZrFl 2 +6Aqj ' R hombohedron. 



K Fl, Ni Fl, 2Zr Fl 2 + 8Aq. . Oblique rhomboidal prism. 



2MnFl,ZrFl 2 + 6Aq\ T , 



2CdFl,ZrFl 2 + 6AqJ * ld * 



2ZnFl,ZrFl 2 +12Aq"l 

 2NiFl, ZrFl«+ 12 Aq } Id. 



2CuFl, 2ZrFl 2 -f 12AqJ 



3CuFl, 2ZrFl 2 + 16Aq. . Id. 



Comptes Rendus, May 21, 1860. 



