272 Scientific Intelligence. 
(4.) Wernerite group.—The “ heteromerous molecules” are a, hav- 
ing the oxygen ratio 1: 2: 3, and }, with the ratio 1: 3:6. Anhydrous 
Meionite =(a); Edingtonite (a)4+-12H; Wernerite, Ist var. =(a-+5) ; 
2nd var. (a+2d); 3d var. (a+64); 4th, (a+12b). Wernerite = (0). 
example, truth and the highest generalizations are not the best displayed 
by simply giving the oxygen ratios. We cannot suppose such com- 
pound molecules actually to have existence in the above (a-+-d) miner- 
als. They are at the best, imaginary quantities for the convenience of 
classification. | 
Mineralogical Notes by Prof. E. J. Chapman, (Phil. Mag. [4], iii, 141 
Crednerite.—R. ‘in )8 
Mn?. 
; 7 
atoms of base and acid.” e formula of helvine, 
(Be, Fe) Sit oMn Si+ Mns, 
becomes on the above hypothesis, 3 atoms of (Mfn, Mn S) and 3 atoms 24 
i [ 
garnet, for the protoxyds, peroxyds and silica is 1: 1:23 whic 
the ratio of 1: 1 for the oxygen of the bases and the silica,—if we spp 
pose that the peroxyds and protoxyds replace one another, as is sho 
to be true in very many cases by Gerhardt. This view appears t ve 
better sustained as a general principle, than that of the mutual substl- 
tution of Si and #, although instances of this last exist. In either cases 
the relation of helvine to garnet is made out, as stated by Mr. Chap- 
man ; for the above formula becomes thus, #Si+(Mn, Mn S)* Si, which ' 
essentially the usual formula of garnet, having the ratio 1: 1: 2. The 
identity does not require us to suppose the isomorphous relation of the 
peroxyds and silica.—s. D. p.] 
blance in external characters of phenacite and quartz, is remarked upon 
r . 
_to the quartz group, and it is remarked that if glucina be looke np 
_ & sesquioxyd, there can be no difficulty in placing both phenacile <4 
beryl in that group “On the other hand, if the formula of glucina of 
Be Q, the isomorphism of sBe and §i, and the s SC aioxyd isomorphs ’ 
i a ng ¥ i h 
‘ * Bia e bad 
“otis r : 
2 ge Pei aL ek ae: 
Wn. ae ean ee ea 
wo 4 
