Supply of Water to the Metropolis. "411 



This is another Just cause of complaint in regard to the water, 

 especially in hot seasons. 



To obtain an effectual supply of clear water, free from insects 

 and all suspended matters, we have taken into consideration 

 various plans for filtering the river water through beds of sand 

 and other materials ; and considering this, on many accounts, as 

 a very important object, we are glad to find that it is perfectly 

 possible to filter the whole supply, and this within such limits in 

 point of expense as that no serious objection can be urged against 

 the plan on that score, and with such rapidity as not to interfere 

 with the regularity of service. 



It must, however, be recollected, that insects and suspended 

 impurities only are separated by filtration, and that, whatever 

 substances may be employed in the construction of filtering beds, 

 the purity of the water, as dependent upon matters held in a state 

 of solution, cannot be improved by any practicable modification of 

 the process. If, therefore, it can be shown that water taken from 

 the parts of the river whence the companies draw their supplies, 

 either is, or is likely to be contaminated by substances dissolved, 

 or chemically combined, it will follow that the most perfect system 

 of filtering can effect only a partial purification. 



From the commencement of our inquiries we have bestowed 

 considerable attention upon this subject, and have endeavoured to 

 obtain accurate information respecting it. But on examining 

 such analyses of the water as had already been made, and were 

 communicated by the companies, as well as by several individuals 

 of high authority onnhese matters, we found them to be so far at 

 variance with each other as to prevent our drawing from them 

 satisfactory conclusions. We, therefore, devised a more regular 

 plan of procedure, which we conceived would be better suited to 

 the particular objects of our present inquiry. After all the pre- 

 parations for that purpose were completed, the occurrence of a 

 heavy fall of snow, the effects of which on the water of the river 

 would have introduced uncertainty in the results, induced us to 

 defer for a time the execution of our plan. We waited till the 

 river had returned to what may be regarded as its average state, 

 and under these circumstances, directed portions of water to be 

 taken, under the personal inspection of our secretary, from dif- 

 ferent parts of the river at different times of the tide, and es- 

 pecially from those parts whence the companies draw their water; 

 and also from situations higher up the river, where its quality 

 can in no degree be influenced by the tide. With the view of 

 comparing the state of the Thames water at London under differ- 

 ent circumstances, we subsequently procured specimens from 

 several parts of the river after an abundant fall of rain ; and also 

 others from places where it had been represented to us as par- 

 ticularly charged with impurities. A popular notion having 

 prevailed that the water in the London Dock possessed peculiarly 

 deleterious qualities, from an impregnation of copper derived 



