410 On the Chemical Composition of Phosphatic Minerals 
Montanchez, and other places in the province of Estremadura, in 
Spain. 
Portugal also possesses extensive phosphate mines, and from 
both countries many thousand tons are annuallj' shipped to 
England at the present time. 
Dr. Daubeny, who visited the Logrosan deposits in company 
with Captain Widdrington, stated in his report, published in the 
' Royal Agricultural Society's Journal ' for 1845, that he found 
the deposits of the richest quality, and to be practically in- 
exhaustible ; but that the want of roads, and the expense of 
transport to Lisbon, the nearest shipping port, about 250 miles 
distant from the mines, rendered them valueless until better 
means of communication should open up the country. 
Since the opening of the line of railway connecting ^Madrid 
with Lisbon, in 1867, numerous Spanish and Portuguese phos- 
phate mines have been partially developed, mainly through the 
instrumentality of companies under the Limited Liability Act 
of 1862. After carrying on the mining operations for a few 
years, and sending the produce to England, most of the com- 
panies, for one reason or another, have been cut short in their 
existence. 
The chief drawback in working Spanish phosphate mines 
successfully is the want of good roads, and the heavy expense 
which has to be incurred in carrying the produce of the mines 
on the backs of mules to the nearest railway station, and thence 
to Lisbon. 
The means of communication in the districts where the 
phosphate mines occur have been greatly improved of late 
years ; still there is ample room for further improvement in that 
respect, and in the mean time the Spanish phosphate mines are 
but little developed. There can be no doubt, however, that 
these mines will furnish at no very distant period a considerable 
proportion of the yearly supply of phosphatic minerals, for 
which there is a constantly and rapidly increasing demand. 
Phosphorite of Logrosan has a light yellow colour, and a fibrous 
crystalline structure, and is more or less interlaced with veins 
of quartz. It is hard and difficult to powder, and becomes 
phosphorescent on heating. The phosphate from the Cacercs 
mines is softer, and of an almost perfectly white colour. 
Generally speaking, Spanish and Portuguese phosphorites have 
either a white or only slightly yellow colour. The produce of 
different mines varies much as regards hardness and richness 
in pliosphate of lime. 
Phosphorite is frequently found in Spain in solid beds, 
varying in dimensions, and alternating with beds of limestone 
