M. P, Berthier on the Phosphate of Lime. 327 
perceived to be chiefly composed of phosphate of lime. This 
specimen had absolutely the same appearance as the argillaceous 
carbonate of iron, and the ticket attached to it indicated that it 
was found under the same circumstances, that is to say, in kid- 
neys, in the bituminous shales that accompany the coal. It was 
lenticular, of the size of the fist, homogeneous, very fine granu- 
lar, having some lustre in a very strong light, and of a deep grey 
colour. The argillaceous carbonate of iron, of the coal deposit, 
often contains phosphoric acid, and even in considerable propor- 
tion ; but until now, the phosphate of lime, in a nearly pure 
state, has not been observed in this formation. The fact, inte- 
resting as it is in a geological point of view, deserves also the 
notice of metallurgists, and should induce them to institute a 
strict examination of the ores with which the coal deposits fur- 
nish them. 
The specimen of the Fins phosphate of lime, on 
lysed, yielded the following results : 
being 
ana- 
Lime, - 0.363 
Phosphoric Acid, - - 0.310 
Phosphate of Lime (apatite), 
0.670 
Protoxide of Iron, - - 0.096 
Carbonate of Iron, 
- 
0.157 
Alumina, - 0.090 
Alumina, 
. 
0.190 
Water, Bitumen, & Carbonic Acid, 0.120 
0.979 
Water and Bitumen, 
- 
0.060 
0.977 
Heated, without addition, in a covered crucible, it melts into 
a compact, opaque, stony mass, covered at the surface with small, 
shining metallic grains. Assayed with half its weight of borax, 
it produces a glass} T and enamelled scoria, and very fragile gra- 
nules, which have scarcely any action upon the magnetic needle. 
M. Jules Guillemin, a pupil of St Etienne, attached to the 
mines of Fins, has addressed to me a note, dated the 31st July, 
which contains some interesting information relative to the geo- 
logical position of this ore, and to its ordinary mixtures. I here 
subjoin an extract from this note. 
“ This mineral is in nodules of a globular form, sometimes 
flattened, always of a rather small size. These nodules occur in 
great quantity in the black argillaceous schists, which separate 
the second bed of coal from the sandstones that support it ; they 
are not homogeneous ; their crust is almost entirely composed 
of carbonate of iron. Sometimes they contain a great quantity 
