SCIENTIFIC SUMMAKY. 
213 
nician origin.” If so, we must inquire what other language will assist us. 
In the Anglo-Saxon, ses is a rock or stone ; sessi, a settle or seat ; sesan or 
sesen, rocks. The e in sesan is without accent, and sounded like e in there, 
ai in fair, or as apres (Fr). The word Sarsen is pronounced by the country 
people sasen, omitting the r ; so thatj perhaps, the word Sarsen is no other 
than the Anglo-Saxon Sesan, “rocks,” and correctly sounded by the Wilt- 
shire descendants of our Saxon forefathers, who still retain many other 
words of the same origin in great purity ; for, as Dean Trench has observed, 
“ they have not gone from us, but we from them.” 
The Nature and Formation of Flint . — At a meeting of the Geologists’ 
Association, held January 2, Mr. M. H. Johnson, F.G.S., read a paper on 
this subject. The object of the paper was to show the nature of several 
members of a large group of bodies occurring in sedimentary deposits of 
different ages, and which are generally known as nodules, and described as 
concretionary. Those specially alluded to were the Septaria from the 
London and Kimmeridge Clays, the Flints from the Chalk, Iron Pyrites 
from the Chalk, the Phosphatic nodules of the Gault, the Clay Ironstone 
nodules of the Carboniferous series, and the Ironstone from the Woolwich 
Beds. By the gentle action of solvents the structure of these bodies is 
revealed so as to be easily examined b} r the microscope. They are then 
found all to agree in possessing a silicified organic structure, which may be 
described as a network of fibres, or a mass permeated in every direction by 
anastomosing canals. This structure was subsequently filled in with other 
material, such as carbonate of lime, silica, bisulphide of iron, phosphate of 
lime, carbonate of iron, &c., the particular substance thus filled in depending 
upon the relative abundance of the substances dissolved in the interstitial 
water of the surrounding matrix. 
Mode of Occurrence of the South African Diamonds . — A paper was read 
on the mode of occurrence of the South African diamonds, before the Geo- 
logical Society of London, by Mr. E. J. Dunn, and is published in the 
“ Geological Magazine ” (January, 1874). In this the author stated that the 
diamonds of South Africa occur in peculiar circular areas, which he regards 
as “pipes,” which formerly constituted the connection between molten mat- 
ter below and surface volcanoes. The surrounding country consists of hori- 
zontal shales, through which these pipes ascend nearly vertically, bending 
upwards the edges of the shales at the contact. The rock occupying these 
pipes was regarded by the author as probably gabbro, although in a very 
altered condition. Intercalated between the shale-beds there are sheets of 
dolerite, &c., and dykes of the same rocks also intersect the shales at fre- 
quent intervals. Within the pipes there are unaltered nodules of the same 
dolerite. With regard to the relation of the diamonds to the rock of the 
pipes in which they are found, the author stated that he thought it probable 
that the latter was only the agent in bringing them to the surface, a large 
proportion of the diamonds found consisting of fragments. At the same 
time he remarked that each pipe furnished diamonds of a different character 
from those found in other pipes. 
Discovery of a New Species of Fish of the genus Acrolepis in the Mill- 
stone Grit of Yorkshire . — At the monthly meeting of the Manchester 
Geological Society, held on the 27th of January last, Mr. John Aitken, 
