80 
Ordinary Meeting, December 14th, 1858. 
W. Fairbairn, F.R.S., &c.. President, in the Chair. 
T.he conversation on the subject of Dr. Joule’s Paper was 
resumed. Mr. Spence insisted upon the advantage which 
would result if the system he had proposed some months ago, 
that of disinfecting sewage by introducing the products of 
combustion from chimneys into the sewers, were adopted. 
He hoped to be able to make an experimental trial at his 
works shortly. Mr. Binney stated that he had reported on the 
condition of the rivers of Manchester twenty years ago, but 
the Corporation had gone on sewering into the streams ever 
since, and this system had been copied, with pernicious 
effects, by the neighbouring small towns. The streams were 
now everywhere thoroughly contaminated. Mr. Hopkins 
explained what had been done in Manchester, and alluded to 
the evil which arose from the large number of exposed middens. 
He considered it an important feature of Dr. Joule’s plan, that 
it could be tried on a small scale. Mr. Mc’Dougall adverted 
to the enormous deterioration of air, which had been observed 
by Dr. Smith to have taken place in the confined yards 
behind houses. He pointed out the great importance of 
disinfecting sewage, both on sanitary grounds and also to 
preserve the fertilizing property. In reference to the latter, 
he mentioned the result of an analysis of urine which had been 
kept some time after it had been treated with his and Dr. 
Smith’s disinfecting agent. It was found that the urea had 
not suffered decomposition. But in another untreated speci- 
men, kept for the same period, the urea had become converted 
into ammonia, of which nearly the whole had been dissipated. 
Mr. Roberts proposed to build tunnels under the streets. 
These tunnels might contain the water and gas pipes. On 
the floor of the tunnels a railway might be placed, by means 
of which the contents of the receptacles of sewage could be 
carried away without pumping. Although the first outlay 
Proceebings No. 6. — Session 1858-9. 
