pivasaing 
XXIV. 
ON THE NATURE AND SPEED OF THE CHEMICAL 
CHANGES WHICH OCCUR IN MIXTURES OF SEWAGE 
AND SEA-WATER. By PROF. EH. A. LETTS, D.Sc., Pu.D. ; 
R. F. BLAKE, F.1.C., F.C.S.; W. CALDWELL, B.A.; anp 
J. HAWTHORNE. B.A. 
[COMMUNICATED BY DR. W. E. ADENEY, F.I.C., F.C.S.] 
[Read Marcu 21; Received for Publication Marcu 23; Published Juny 27, 1900.] 
Ir need scarcely be said that one of the commonest methods 
adopted by towns situated on the coast, for the disposal of their 
sewage, is to run it without treatment of any kind directly into 
the sea. 
Mr. Richard Hassard has given us the following list of the 
chief towns in Great Britain which adopt this plan :— 
Aberdeen. Birkenhead. Brighton. 
Dundee. Hull. Portsmouth. 
Berwick-on-T weed. Great Grimsby. Sidmouth. 
Newcastle. Yarmouth. Teignmouth. 
Sunderland. Margate. Devonport. 
Scarborough. Dover. Swansea. 
Blackpool. Folkestone. Bristol. 
Liverpool. Hastings. 
And to them may be added the following Irish towns :— 
Belfast. Wexford. Limerick. 
Dublin. Waterford. Galway. 
Londonderry. Cork. 
The nature of the chemical changes which occur when sewage 
is thus treated, the speed at which they take place, the conditions 
which modify either the changes themselves, or the rate at which 
they occur, and the circumstances under which a nuisance may 
arise, are questions all of which are not only of scientific interest, 
but also of practical importance. 
