413 
of greenstone, or a compound of hornblende and felspar, are also 
mentioned by the author. 
No freshwater or marine shells have been discovered in these 
accumulations. 
~. Organic remains derived from other deposits are very rare, with 
the exception of casts of vegetable origin, Mr. Bailey having found 
only two impressions of shells. Siliceous fragments of stems of 
Sigillaria and Stigmaria occur in every pit, retaining more or less in- 
dubitable marks of their origin, and occasionally exhibiting on the 
surface a smooth, coffee-brown-coloured coating. One specimen in 
the author’s possession, measuring nearly four anda half feet in cir- 
cumference, and weighing about 200 pounds, is stated to retain what 
appears to be a portion of the original bark. 
A large series of specimens accompanied the memoir, and was pre- 
sented by the author. 
A letter, dated February 1840, from Mr. Thompson of Yarrells, 
near Poole, in Dorsetshire, and addressed to Dr. Buckland, was after- 
wards read. 
The object of this communication is to give an account of a bormg 
in search of water at the Union Workhouse, Longfleet, near Poole. 
The first land-sprmg was tapped at the depth of 36 feet, the sur- 
face of the ground being about 90 feet above low tide in Poole Har- 
bour. The water was abundant and rose four feet. The next 
spring occurred at the depth of 127 feet, and others burst forth 
at 131 feet, 140 feet, 142 feet, 150 feet, 156 feet, 165 feet, 167 feet 
and 185 feet, from the surface. They all flowed to the same height, 
and appeared, Mr. Thompson states, to have been fed from the same 
source. he next spring was encountered at the depth of 235 feet, 
in a bed of white sand; it flowed six feet higher, and was more 
abundant than any of the preceding. The spring which issued 
from the bottom bed was still stronger, and rose 23 feet higher than 
any of the others, or to within 24 feet of the surface. The lowest 
pipe introduced into the boring had a diameter of three inches ; it 
was worked with “ two-lift pumps,” the section-pipe of each being 
two inches bore, for nine hours incessantly, during which 25,728 
gallons were discharged. An analysis of the water was made by 
Mr. J. H. Cooper, and a gallon was found to contain 95 grains of 
solid matter, or 44 grains of oxide of iron, the remainder consisting 
principally of common salt with a small admixture of sulphate and 
carbonate of lime, and a trace of oxide of manganese. 
At Hamworthy, near Poole, another boring has been made, within 
100 yards of the harbour, to the depth of 314 feet, through a 
series of beds similar to those penetrated at Longfieet, and a similar 
series of springs was tapped; but as the boring was commenced at 
80 feet lower level, or only 10 feet above low tide in Poole Harbour, 
all the springs flowed over the surface, though not strongly. ‘This 
boring was abandoned on account of the sand which accumulated 
in the pipe. 
