318 
POPULAE SCIENCE EEYIEW. 
suspended and least oxidisable portion of the sewage. 3. The river water 
supplied in London is often very imperfectly filtered; and thus even the 
visible suspended matters of sewage are not wholly excluded from the water 
supply. Only on one occasion during the whole year 1867, have I obtained 
a transparent sample of water from the Southwark Company’s mains. The 
Grand Junction Company’s water was turbid four times out of twelve ; the 
Chelsea thrice ; the West Middlesex, Lambeth, and East London each twice, 
out of the twelve occasions when the samples were drawn for analysis. The 
New River Company alone delivered perfectly filtered water during the 
whole year. 4. The quality of the water supplied to London is greatly 
inferior to that of any other town in the United Kingdom, whose supply I 
have examined. 6. The distribution of water in the metropolis still con- 
tinues, with but slight exceptions, on the intermittent system, a system 
which has been abolished in almost every town of importance in the United 
Kingdom. 6. The water which it is proposed to supply either from the 
Welsh or the Cumberland districts is of excellent quality. It is equal or 
superior to that supplied to any town in Great Britain. 7. The water from 
each of the proposed districts is extremely soft, pleasant to drink, and of 
good a&’ation. 8. These waters have never been contaminated with sewage, 
and are therefore above all suspicion. 9. They can be distributed in the 
present system of supply pipes without any danger of lead contamination. 
GEOLOGY AND PALAEONTOLOGY. 
Neiv Fossil Reptiles from South Africa . — The Geological Magazine for May 
contains a paper illustrated by two capital lithographs, upon two forms 
of lacertilian reptiles which have been exhumed from the British Museum 
by Professor Rupert Jones, and which are now described by Professor 
Huxley. Professor Huxley says, that the matrix is the same as that in 
which the dicynodonts are embedded, but in the case in point the skeletal 
remains are not those of dicynodont, but of a lacertilian allied to Telerpeton, 
and about seven or eight inches long. For detailed description we must 
refer our readers to the excellent plates which accompany the paper. Pro- 
fessor Huxley calls the fossil Saurosternon Bainii, in compliment to Mr. Bain, 
who brought the specimen over from Africa. 
The Cause of Contortion and Faults is the subject of a short paper by 
]\L’. J. M. Wilson, of Rugby School. Mr. Wilson thinks that the explana- 
tions of the phenomenon in books are extremely unsatisfactory, and he gives 
a mathematically worked-out hypothesis of his own. He considers that 
contortion and faults are readily explained when one recollects : (1) That 
depressions and elevations take place over large areas ; (2) That the surface of 
the earth is curved ; (3) That rocks are compressible by foldings ; (4) That 
rocks are not extensible or elastic ; and (5) That at great depths rocks are 
somewhat plastic through heat. — Vide Geol. Mag., No. 47. 
The Fossil Insects of North America. — Mr. Samuel Scudder, of the Boston 
Society of Natural History, is so well known to students of fossil insects, 
