402 On the Chemical Composition of IViosj}Jiatic Minei-als 
Composition of Two Samples of Supkrior French Coprolitbs. 
No. 1. 
No. 2. 
Moisture and water of combination 
2-79 
2-95 
25 10 
27-76 
40-11 
41-88 
14-38 
10-56 ■ 
7-10 
17-62 
9-75 
100-00 
100-00 
54-79 
60-60 
16-14 
The sample No. 1 was taken from a bed at Bellegarde, in 
the south of France, consisting almost entirely of various 
phosphatic fossils, such as numerous varieties of terebratula, 
belemnites, ammonites, and sea-urchins, in a more or less 
perfect] V entire state. Both samples were much lighter in' 
colour than" Cambridge coprolites ; they were also softer, and 
more readily ground to powder. The second sample, it will 
be observed, contained about as much phosphate of lime as 
first-class samples of Cambridge coprolites, and not much 
more carbonate of lime. 
Perhaps the most valuable coprolite deposits in France occur 
in the Ai'dennes ; these deposits are as yet but partially de- 
veloped. The cost of carriage is too great to render it probable 
that French coprolites, except those found close to the coast 
near Boulogne, will be largely exported into England. It is 
even doubtful whether the export of the latter will prove a 
paying speculation, for, as already stated, Boulogne coprolites as 
a rule seldom contain more than 45 per cent, of phosphate of 
lime, and they are too much impregnated with oxide of iron 
and alumina, two constituents which considerably lower the 
commercial value which they otherwise would possess. They 
fetch in the market a much lower price than good Cambridge, 
or Bedfordsliire, or Norfolk coprolites; and under present con- 
ditions the importation of Boulogne coprolites into England, at 
the best, leaves but a scanty profit to dealers and exporters. 
The composition of French coprolites varies to some extent, 
as will be seen by the subjoined Table showing the general 
composition of several cargoes, samples of which have been sent 
to nie for analysis : — 
