[October, 
558 Notices of Boohs. 
can contend that the colouring matters of logwood, fustic, peach- 
wood, &c., if present in a river are likely to be injurious to man, 
beast, or plant. But who knows what accompanying and really 
noxious pollutions they may hide ? On this account we think 
that transparency and the absence of colouration are character- 
istics to be desired, especially as they may be attained by known 
methods. 
The author continues •“ Neither do the decisions of the 
judges either in courts of law or equity furnish a definition of the 
word such as to meet the requirements of the Adt.” As the only 
way of solving the difficulty he gives a summary of the expressed 
opinion of scientific men. Under this head we find once more 
the recommendations of the Rivers’ Pollution Commissioners, 
on which surely nothing further need be said, especially as they 
have not been deemed fit for legislative adoption. Mr. Higgins 
gives along with them some — though by no means all — of the 
objections raised against them. He then quotes with marked 
approval the two recommendations given by Mr. Crookes, 
F.R.S., in his evidence before the Committee of the House of 
Lords. These are simply that the river itself should be the 
standard of purity, and that no liquid should be permitted to fall 
into a river if such liquid contains a greater percentage of im- 
purity than the river itself. These suggestions, Mr. Higgins 
thinks, may be safely followed by county court judges in their 
decisions under the Acft. 
As regards solid matter thrown into rivers another difficulty 
arises. “ No offence against the Adt is committed unless 
the solid refuse, rubbish, cinders, or other waste or putrid 
solid matter finding its way into the river results either in 
interfering with its due flow or in polluting its waters." Here, 
we fear, the Adt is scarcely stringent enough. The gradual 
silting up of rivers from natural causes is a source of danger 
which requires to be jealously watched and contended against, as 
the records of the past winter will show but too plainly. Surely, 
then, it is intolerable that the evil should be intensified by the 
sloth or the greed of those who would make the rivers general 
depositories of filth and refuse of all kinds. On this subjedt the 
Rivers Pollution Commissioners in 1868 spoke very judiciously. 
They recommended that not merely “ the casting of solid matter 
of whatever kind into rivers and running water ” should be pro- 
hibited, but also the placing of solid refuse in such positions on 
the banks of rivers as to render it liable to be washed away by 
floods.” They also suggested that any Adt passed for this 
purpose should take effedt immediately. 
In treating of sewage and of liquid manufacturing refuse, Mr. 
Higgins, though himself a chemist, and far better qualified to 
speak on the subjedt than many who have come forward as the 
instrudtors of the public, does not enter into the comparative 
value or efficiency of the various methods of dealing with polluted 
waters. 
