Vol. 58. ] THE MATRIX OF THE SUFFOLK BOULDER-CLAY. 179 
11. On the Marrix of the Surrorx Caarxy Bourper-Cray. By the 
Rev. Epwin Hutz, M.A., F.G.S. (Read February 5th, 1902.) 
Mucs# study has been bestowed upon the boulders included in the 
Glacial Clays, their nature, origin, and distribution. The matrix in 
which they lie has received comparatively little attention. Yet the 
matrix, in many or most, forms by far the largest part. I have 
been endeavouring to study this matrix under the microscope, by 
washing it, shaking it up with water, and so separating the material 
which will settle quickly to the bottom from that’ which remains 
longer in suspension. The process has to be repeated until the water _ 
remains clear, else dust still suspended dries on the surfaces of the 
grains which had settled and masks them from examination. I have 
collected and dried this finer dust, but it cakes together: I have not 
obtained from it much information. The coarser material, that 
which subsides first, forming from 40 to 75 per cent. of the whole, 
dries to a sand or powder and lends itself readily to examination 
with the microscope. I have tried several methods, and have 
succeeded best by inspection under direct daylight of the powder 
strewn ona slide. Inspected in this manner, Glacial Clays from 
localities in Hast Anglia tell something of their sources. I have 
examined specimens from places along a belt of counfry in Suffolk 
extending from Lowestoft to Bury St. Edmunds, a distance of more 
than 50 miles; Lincolnshire material dredged up in deepening the 
ship-channel to Boston (kindly sent by Mr. W. H. Wheeler, C.E.) ; 
Cambridgeshire specimens from Ely Cemetery and from the 
neighbourhood of Bishops Stortford (the latter kindly sent by the 
Rev. Dr. A. Irving) ; and a Middlesex specimen from the Marylebone 
Cemetery, Finchley. 
The coarser residuum, after washing these clays, is a sand or 
powder containing grains of quartz, chalk, chert, and other homo- 
geneous minerals, generally some sponge-spicules, a few fragments 
of shells, and occasionally foraminifera, probably derived. Besides 
these many samples contain granules which are portions, generally 
rounded, of grey or dark limestone or clay. Some contain cream- 
coloured granules which seem to be of a limestone. In some are 
granules which appear to be mere aggregates of sand-grains cemented 
together. Ina sample from the Boston dredgings there are granules 
of sand-grains in a chalky paste. <A pit about 2 miles south-east 
of Saxmundham, where clay is resting on some sands, affords, in the 
residue from the clay, fragments, not rounded, of a quartzite which 
reminds me of sarsenstone. The grey clay- and dark limestone- 
granules are found in the samples from League Hole and Corton 
(north of Lowestoft), Halesworth, a pit 1 mile south-west of 
Saxmundham, Stowmarket, Norton and Woolpit (about 7 miles east 
of Bury St. Edmunds), Cockfield (about 7 miles south of Bury), and 
also in the specimen from Finchley (Middlesex). The cream-coloured 
Q.J.G.8. No. 230. 0 
