O. C. Marsh on Ledererite from Nova Scotia, 365 
water, as given in No, la, and then fused with carbonate 
of soda, and its silica separated. A portion of the same min- 
No, 1, was 2-108 ; in No, 2, 2°099, and the hardness in each 
case was about 4:5. The other physical, and the pyrognostic 
characters of the mineral, corresponded essentially wit ose 
observed in typical Gmelinite. The results obtained in the 
analyses were as follows :— 
2 2. 
see ae ye 
Miligh Ss saw. caus 53°71 aes 51°32 
Aboraiua, ss is digs 17°63 18°45 
ROB: as « tinnemamn 6°52 6°40 
Otay sc cnacees ices ae : 
ERA 3°10 } by toes, 3°48 
Phosphoric acid,. .. trace ee es 
Pere a 17°98 reg 20°35 
99°74 100.00 
On comparing these results with those obtained by Dr. 
Hayes in his analysis, the only one previously made of Leder- 
erite, it will be seen that they differ widely in respect to the 
amount of phosphoric acid and water—the two important points, 
in fact, which had occasioned discussion as to the nature of the 
Mineral. It should perhaps, be added that in consequence of 
discussion, special precautions were taken to guard against 
error in determining these substances. The small amount ot 
Material at command, rendered it —— to repeat the analy- 
What has long been suspected, that the phosphoric acid, found 
by Mr. Hayes, must be 2 as an impurity, and that Led- - 
i ter as Gmelinite 
| as: e, 
and hence is identical with that species. The evidence of this 
ty becomes still more apparent on comparing the compo- 
