452 Chemical Description of [J ung, 
method is found to afford a better preparation than was formerly 
obtained from twice the quantity of cinchona. 
The stratum of bark should be of such a thickness that the water 
may neither pass through too slowly nor too rapidly. I have found 
astrainer of two inches, three inches, or four inches diameter, most 
suitable for 1 0z., 1 0z., or 2 oz. of cinchona. 
I remain, Sir, your obedient servant, 
Lancaster, April 15, 1817. C. JoHnson. 
Articite VII. 
Abstract of « Memoir entitled Examination of some Minerals 
"found in the Neighbourhood of Fahlun, and of their Situation. 
By J. G. Gabn, J. Berzelius, C. Wallman, and H. P. Eggertz. 
Inserted in the fifth Volume of the Afhandlingar i Fysik, Kemi 
och Mineralogi.* 
Tax neighbourhood of Fahlun being remarkable for the great 
variety of uncommon minerals which have been found in it, Messrs. 
Gabn, Berzelius, Wallman, and Eggertz, undertook to examine 
them, both in a mineralogical and geognostic point of view; and 
in the excursions which they made last summer for that purpose 
their attention was fixed chiefly on the excavations at Finbo, 
While analyzing the deuto-fluate of cerium, and the double 
fluate of cerium and yttria, Berzelius found in them a new earth, 
which he had extracted the preceding year from the gadolinite of 
Korarvet, but in too small quantity to be able at that time to deter- 
mine its properties with the requisite precision. I shall extract from 
the memoir in question every thing that concerns the new earth. 
Minerals in which the new Earth is found. 
The neutral deuto-fluate of cerium of Finbo is of a deeper red 
than that of Broddbo. It is sometimes found crystallized in six- 
sided prisms, the length of which exceeds the breadth, sometimes 
in plates more or less thin, and sometimes in irregular amorphous 
masses. It is imbedded in a rock composed of albite, quartz, and 
mica, and is accompanied by emeralds and yttro-tantalite ; but it 
occurs so sparingly that all the specimens which we found were 
hardly sufficient for a single analysis. J satisfied myself, therefore, 
with ascertaining by small experiments that it is a neutral fluate of 
cerium ; and by means of the blow-pipe I have satisfied myself that 
* This volume has not yet been published. For the present abstract I am in- 
debted to the Chevalier d’Ohsson, who kindly translated it from the Swedish 
sriginal, of which le was possessed of a copy.—T. 
