THomson,—On the Cleansing of Towns, 68 
mud aud sewage mud ;" that “sewage does not work its way up the river;" 
and, finally, that “the muddy condition of the river is caused principally 
by the unprotected state of its banks," 
Here, then, we may pause and exclaim, How doctors differ | 
Captain Calver supports his statements by numerous tables and analyses, 
and Sir J. W. Bazalgette does the same in treble volume, hence his 
chemical referees quaintly conclude their support of their employer by a 
remark, viz., conclusions of a few samples only (by Captain Calver’s 
analysts) must be looked upon with great distrust ! 
The report of Sir J, W. Bazalgette is accompanied by an appendix con- 
taining letters and reports of other authorities, besides plans, charts, and 
sections of the Thames and its estuary. The evidence of Faraday is 
brought out as to the former foul state of the Thames within the city pre- 
cinets, and apart from the question before us the charts of the saltings or 
erosions of the banks of the Thames estuary are interesting to the physical 
geographer. And here we may take the liberty of pointing out that, as 
these all take place below the sewage outfalls, extending for a distance of 20 
miles, from which Sir J. W. Bazalgette ascribes the muddy condition of the 
river above—from this, his own principle, we have a difficulty in clearing 
him from contradiction, when he ignores Captain Calver’s statement in the 
same direction, viz., that the filthiness of the river above the outfalls, 
extending up to London, little more than 10 miles, is due to the sewage 
deposits of Barking Creek and Crossness, which is but a corollary to his 
own theory. 
But, in truth, the controversy is of a kind in which one throws his filth 
into a neighbour’s bed, so complete equanimity is not to be expected, on the 
contrary, perturbations from the true mean of sound judgment are to be 
looked for. It is open, therefore, to the enquirer to suppose, that as the 
sewage issues from the outlets into the Thames with the ebb, weightier 
particles will be the first to descend to the bed not far from the outlets; 
hence, may it not be supposed that, when the advancing flood of the heavier 
salt water, forcing itself beneath the lighter fresh water, yet ebbing at the 
surface, arrives at the outlets, these weightier particles will be carried 
up the river to certain distances? In the notesof experiments, on either 
side of the question, we do not detect that sufficient investigations have 
been made on this point. It is, therefore, yet unsettled, and can here only 
be alluded to. 
But to the general public this subject carries little interest with it, for 
to those acquainted with the Thames near London, 25 years ago and now, 
the enormous improvement in the cleanliness of its waters is palpable. 
