32 On the Value of Phosphatic Rocks of the Anguilla hies. 
The specimens sent home from the Sombrero Rock contain 
lespectively — solid rock, 36'71 per cent, of phosphoric acid or 
80'14 of phosphate of lime. The porous portion of the rock 
}ielded 32-37 per cent, of phosphoric acid or 70 67 of phosphate 
of lime. 
Now, although these specimens are much richer than those 
transmitted from the Anguillas, it is to be recollected that the 
former were taken from the heart of the rock ; the Americans 
having cleared away all the overlying portions, even to the 
water's edge. On the other hand, the British specimens were 
merely gathered from the surface : and it is therefore probable 
that, when deeply quarried into, some of our " keys " may prove 
as valuable as the Sombrero rock. 
We have yet to learn to what extent other rocks of the Anguilla 
Isles may be of as good a quality as those of the " Little Scrub ;" 
but even if it be found that Anguilla, the chief island, of the 
group, which is 20 miles long by 6 miles broad, does not contain 
any considerable quantity of this peculiar breccia, still the islets 
lying between it and the rock of Sombrero may be of considerable 
value. For, if substances similar to the breccia of the " Little 
Scrub " — which has all the external character of a bone breccia 
— shall be found to occupy several of these islets, the discovery 
must be considered one of great national importance, in pro- 
viding our agriculturists, from a British possession, with a plen- 
tiful supply of a good substitute for the guano of Peru. 
I trust, then, that Her Majesty's Government may deem it 
expedient to send out a competent geologist, or may direct one 
of the two geologists now surveying in the West Indies, to 
explore the "keys" and rocks at Anguilla, and define the extent 
over which these phosphatic substances may be distributed. 
Museum of Practical Geology and Government School of Mines, 
Jermyn Street, May 30, 1859. 
IV.' — The Agriculture of the Islands of Jersey, Guernsen, Alderney, 
and Sark. By C. P. Le Coexu, Beaumont, Jersey. 
Prize Essay. 
J ERSEY. — The Channel Islands in former times were very little 
known beyond the fact of their existence, but they may be said to 
have awakened as it were from a state of lethargy, and become a 
highly important although a small section of the British empire. 
Within the limits of these pages it being necessary to confine 
