Penrose. J PHOSPHORITES OF SPAIN. 
Table of analyses of phosphorites from southwestern France— Continued. 
[II. Analyses by C. U. Shepard", jr.] 
53 
Phosphoric acid 
Equal bone phosphat 
Sand 
Hi<rh-grade 
phosphorite, 
from Mas- 
Merlin. 
38.64 
84.35 
1.00 
Low-grade 
phosphorite, 
from 
Larnagol. 
21. 4G 
46.85 
14.58 
Superphosphates made from 12 parts (by weight) of rock and 9 parts 
of sulphuric acid (1.50 specific gravity) gave: 
High grade 14. 98 per cent, soluble phosphoric acid. 
Low grade 5. 04 per cent, soluble phosphoric acid. 
1 III. Analyses of commercial Bordeaux phosphate by C. TJ. Shepard, jr. 
< 
I. 
II. 
35.46 
77.41 
4.35 
34.45 
75.20 
8.55 
Superphosphates made in the same way as the last case gave : 
I. 
15.00 
12.48 
PHOSPHORITES OF SPAIN. 
The phosphorite deposits of Spain are situated near the towns of 
Logrosan and Caceres, in Estremadura. The two localities differ some- 
what in the mode of occurrence of the phosphorite as well as in its 
physical properties, and will therefore be treated separately. 
Logrosan deposits. — The country in which these occur is a broad table- 
land composed of a clay slate and studded here and there with couical 
peaks rising abruptly from the level of the plain, and often reaching 
the height of three hundred to six hundred feet above the surrounding 
surface. There also occur numerous long, flat ridges, rising, like the 
peaks, abruptly from the surface of the plateau. The slate is of very 
variable character, being composed sometimes of a dark-blue, fissile 
schist, sometimes of a micaceous or a talcose schist, and at other times 
of alternating beds ot talc and feldspar. 1 No fossils are found in this 
formation, but in a very similar deposit near Almaden, and about 
eighty miles from the town of Logrosan, are found numerous fossils, 
1 Charles Daubeny and Captain Widdrington : Jour. Roy. Agric. Soc, 1845. 
(527) 
