I885.J 
Analyses of Books. 
161 
decidedly as can putrescent matter. And though the recom- 
mendations of the late Rivers’ Pollution Commission, which 
“ schleppen sich 
Wie eine ewige Krankheit fort,” 
fix no bounds to the proportion in which magnesian salts may 
unsafe red ^ * nVei '’ adli0n iS ^ the long rUn decidedl y 
hi discussing the condition of the Thames above London 
Mr. Kingzett makes a statement which cannot be admitted! 
He writes: “ I he treatment of sewage, as here referred to 
means the removal therefrom of the whole of the suspended 
matters, but it does not seriously affedt the composition of the 
liquid part (effluent) which is then discharged into the river.” 
But, if the treatment is properly performed, soluble organic 
mattei, such as soluble albumen, will be coagulated, precipitated 
and removed. We may withdraw from town sewage, by the 
most careful and reiterated filtration, all suspended matter. Yet 
on adding to the filtrate solutions of certain metallic salts 
preferaoly perhaps of aluminium chloride,— a precipitate is pro- 
duced consisting of a compound resembling the “ lakes ” of the 
colour-maker and the dyer. 
In examining the dogma of the Rivers’ Commissioners, that 
Rivers which have received sewage, even if that sewage has 
been pui lfied before its discharge, are not safe sources of potable 
water, Mr. Kingzett presses the question— How is it, consider- 
ing the quantity of organic matter introduced into the Thames 
that its water is so comparatively pure ? He points to the 
various agencies, organic and inorganic, which take part in this 
purification. According to some experiments made by Prof W 
Odling the water of the Thames loses daily, in passing from 
Teddington Lock to Somerset House, from 12 to 13 tons of 
oxygen. It is indeed difficult to say what can have become of 
this oxygen unless it has been employed in oxidising, or, in plain 
English, burning up the impurities. 
It is of couise contended that, whilst dead organic matter is 
thus burnt up, living organisms — disease-germs — resist. We 
aie told of experiments said to have been made upon them with 
poisonous gases. If the results described were really obtained 
it may be asked whether the chemicals used are poisons for these 
particular organisms, or are inhaled by them at all? We have 
imprisoned specimens of an animal, very much higher in the 
scale of being, Callidium violaceum , in an atmosphere of hydro- 
cyanic acid, without effedL Other poisons, on the contrary 
proved effectual. 
In reply to Dr. Hogg's celebrated Caterham case, where a 
workman suffering from enteric fever had defiled the well, and 
thus occasioned a disastrous epidemic among consumers oV the 
water, the author shows that the water, though largely diluted, 
