88 Sanitary Vagaries : [February, 
some of these metals — such as chromium, lead, zinc, &c. — 
are formidable poisons, whilst others — such as aluminium 
and iron — are practically harmless in any proportion likely 
to find its way into a river. Surely then aluminium and 
chromium require each a different standard. 
It is a mistake also to suppose that the unlimited intro- 
duction of the salts of sodium, calcium, and magnesium 
into water-courses is a matter of indifference to the health 
of man or beast. In my former article on the sewage- 
question (“Journal of Science,” 1884, p. 256) I remarked 
that it was not demonstrated that “ the carbonates and 
sulphates of lime and magnesia are detrimental to health.” 
But I was here speaking of the calcium and magnesium 
salts only when in such proportion as they are naturally 
found in rivers, lakes, &c. Even the so-called mineral 
springs, though beneficial in certain diseases, are hurtful to 
men in a normal condition, and cannot serve as a domestic 
supply. How much less, then, should it be permissible to 
turn unlimited quantities of these salts into a river ? 
The faCt is that, both as regards mineral and organic 
impurities, the Rivers’ Pollution Commissioners laid down 
arbitrary standards which they have never been able or 
willing to justify. 
But there is little occasion to go into a criticism of details. 
The fundamental principle of fixing a standard for the quality 
of waters which may, or may not, be permitted to flow into 
a river is vicious. All laws adopting it actually court evasion. 
If it is desired to turn into a stream some water which the 
standards would prohibit, nothing can be easier than to 
pump up water from such stream so as to dilute it to the 
degree needed. What, then, will be gained by the standards ? 
As the “ Chemical News” remarks : — “We trust that even 
the inspirers of this Bill will not be able to shut their eyes to 
the faCt that whether we pour into a river daily 100,000 
gallonsof water containing2 partsof organic carbon or 200,000 
gallons containing half that proportion the total quantity 
of pollution conveyed into the river remains the same.” 
There may, and probably will, be found cases where the 
river is worse than the sewage or waste water discharged into 
it. In view of such cases the Bill declares that : — “ It shall 
be no defence to any offence against this ACt to prove that 
after any offence against the ACt has been committed, the 
water of the stream is less polluted than is defined by the 
standards of purity hereinafter mentioned.” I may add that 
should this Bill unfortunately become the law of the land it 
may happen that a manufacturer shall incur heavy penalties 
