I 



INTRODUCTION 13 



I 



The sewage is about 15 per cent, stronger ; the final effluent 

 shows 16 per cent, rise in the oxj^gen consumed and 5 per cent, 

 decrease in the albuminoid ammonia. Water-carriage is now 

 general in towns ; the chief objection urged against it is the 

 waste of the water-supply. But the amount used per day in 

 closets, being rarely measured by meter, has often been over- 

 estimated. If we take the chlorine figures in Frankland's 

 analyses as an approximate measure of the strength of the 

 sewage (see Chapters II. and VI.), we find their ratio to be 11*54 

 to io*66, or nearly 11 to 10 — that is to say, an addition of one- 

 tenth to the ordinary water-suppty has been sufficient to replace 

 the carts and other apparatus, besides the labour, of the pail, 

 earth, and other conservancy systems. Yet at Copenhagen it 

 is stated that in several of the newer houses the water-closet 

 system has been introduced ; but there is a yearly tax of ^^^5 12s. 

 for every seat ! 



Another method of arriving at the amount used is by the 

 volume of flush. Putting this at 2 gallons, and assuming two 

 uses per day per individual, we reach a figure of 4 gallons, 

 or from ^ to tV of the water-supply per head. So that the 

 volume of sewage will not be greatly increased, and its dilution 

 may really favour bacterial treatment. 



The slop-closet^ in which the household slops alone are used 

 to flush away the excreta, effects a saving of water. The 

 relative amounts found in some experiments at Manchester 

 were : Slop-closets 4*5, water-closets 8*8, gallons per head of 

 water consumption per day.^ The obvious fault is the danger 

 of irregularity. 



It may be concluded that wherever an adequate supply of 

 water is attainable the water-carriage system is best. 



Reports of medical officers of health — notably those of York 

 and Durham in 1900 and of Nottingham in 1904 — give statistics 

 proving the connection of the incidence of typhoid with midden 

 privies and with pail collection. 



In one place in North Devon a Local Government Board 

 report in 1902 states that the midden privies had been emptied 

 only twice in the year, sometimes only once in two years, and 

 occasionally there was a pig-sty in connection.- Many of the 

 houses had no water-closets or privy accommodation. At such 

 houses, in some cases, commodes were kept in the bedrooms, 



1 Public Health, March, 1899, p. 419. 

 •^ Public Health Engineer, April 5, 1902. 



