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III. — On the Commercial and Agricultural Value of certain Phos- 
phatic Rocks of the Anguilla Isles in the Leeward Islands. By 
Sir EODEEICK lilPEY MxTRCHISOX, V.P.R.S., Director-General 
of the Geological Survey, and Honorary Member of the Royal 
Agricultural Society. 
Havisg long been an Honorary Member of the Royal Agri- 
cultural Society of Great Britain, I have often regretted that 
I have never had it in my power to communicate anything of 
importance to the British farmer. 
T am now, however, enabled to make an announcement which 
will, I have no doubt, be as acceptable to the readers of the 
' Agricultural Journal ' as it is interesting to the geographer 
and geologist, whilst it is likely to become very valuable to the 
merchant and shipowner. 
A few weeks ago my eminent friend Sir William Hooker 
enclosed to me a letter from His Excellency Mr. Hercules 
Robinson, recently Governor of St. Kitts, in the Leeward 
Islands, and now appointed Governor of Hong Kong, accom- 
panving a box of specimens of rocks taken from three localities 
in the Anguilla Isles, lying immediately to the north of St. Kitts, 
and requesting me to have the specimens analysed in the labo- 
ratory of the School of Mines under my direction. 
It appears that the Americans, in the course of the year 1858, 
quarried away some 30,000 tons of rock, the greater part of an 
islet called Sombrero, to the north of the Anguillas, and sold 
the substance in the New \ork market at prices from 3/. IO5. 
to 6Z. 10s. per ton, to the amount of 100,000/., for the purpose, 
it is said, of regenerating the exhausted lands of Virginia. Sub- 
sequently the inhabitants of the Anguillas, knowing that some of 
their northern " keys " or rocky islets were similar in aspect 
to Sombrero, naturally desired to have these substances analyzed. 
The analyses have been made by Mr. Charles Tookey in the 
laboratory of this establishment, under the direction of Dr. Percy, 
and are as follows : — 
Little Anguilla. — The specimens from this islet do not contain 
a notable amount of phosphoric acid. 
Little Scrub. — This sample contains 1'62 per cent, of phosphoric 
acid or 3'53 per cent, of phosphate of lime ; but certain porous 
portions selected from the mass gave 25'75 per cent, of phos- 
phoric acid or 56"21 of phosphate of lime. The porous portion 
of the Little Scrub rock contains also nitrogenous organic matter 
and a trace of potash. 
Blowing Rock. — This sample contains 0*31 per cent, only of 
phosphoric acid or 0"68 per cent, of phosphate of lime. 
