75 
i88o.] The London Water-Supply . 
On the third condition, the quality of the water, consi- 
derable difference of opinion prevails. All authorities 
appear to agree that the presence of animal and vegetable 
matter in certain states of decomposition, and that of cer- 
tain low organisms, such as baCteria, are occasionally inju- 
rious, and even destructive, to life. As Science is not yet 
able to say, with any approach to precision, under what cir- 
cumstances such putrescent matter and such organisms 
become dangerous, the only safe rule is to insist, as far as 
possible, on the total absence of all organic matter what- 
soever. , , . . . 
But when we come to consider the mineral or inorganic 
matters from which no natural water is absolutely fiee, we 
find certain chemists, engineers, and physicians who advo- 
cate a soft water, — one in which the mineral matters, 
and especially the salts of lime and magnesia, are at a 
minimum. Others, again, no less, strongly give the prefer- 
ence to the hard waters containing a large proportion ot 
these same calcareous and magnesian salts. 
Mr. Bateman regards softness as a very important requi- 
site for the supply of any town ; and after a careful 
consideration of the various purposes, domestic and manu- 
facturing, to which water is applied, we feel compelled to 
take the same view. Hard water in the household may be 
pronounced an almost unmixed evil. It appears probable 
that in London alone the waste of soap, due to the use of 
hard waters, reaches the annual value of £500,000. To 
wash the person with hard water is a true penance. The 
soap is decomposed, and the lime-soap generated forms a 
film over the skin and blocks up the pores, so that the 
effeCts of the operation are the very opposite of what we 
aim at in our ablutions. We have the high authority of the 
late M. Soyer for asserting that in all culinary operations, 
and especially in the boiling of vegetables, better results are 
obtained with soft than with hard water. 
It is very satisfactory to find that Professors Frankland, 
Odling, Ramsay, and Way, and Drs. Farr, Lyon Playfair, 
and Simons coincide in this preference for soft water. 
On the other hand, Prof. Ansted considers it “ certain 
that among the healthiest towns in England are some of 
those supplied with hard water containing both carbonates 
and sulphates.” If we remember, however, that the quality 
of the water supplied to a town is only one of the many 
factors on which its sanitary condition depends, we shall 
scarcely ascribe much weight to what is probably a mere 
coincidence. It so happens that the towns and cities 
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