[June, 
356 Analyses of Books. 
formerly known as carbonic oxide. This gas, as Dr. Fox shows, 
is a fearful poison ; it is produced during the combustion of coke, 
and it permeates heated cast-iron. It is a strange thing that we 
cannot in this country obtain stoves of glazed earthenware, and 
thus economise fuel without inhaling a narcotic poison. The 
author remarks that “ the sun, burning coal, burning wood, hot- 
water pipes, and stoves, give forth heating rays which can by 
some be distinguished in virtue of a difference in the impressions 
afforded.” That such should be the case is, theoretically 
speaking, to be expected, but we fear that few persons could be 
found sufficiently sensitive for the study of these variations. 
Perhaps experimentation on plants or on certain inseCts might 
show whether there is any difference in the physiological acftion 
of heat obtained from difference sources. 
In an essay on the supply of rain-water to/cottages in rural 
districts, Dr. Fox combats the arguments brought forward on 
behalf of hard water as a domestic supply. He quotes Dr. 
Cameron to show that the death-rates of Glasgow and Man- 
chester, and other towns supplied with soft water, were not lower 
when the water furnished to them was hard, and that the public 
health of Dublin has improved since the substitution of the soft 
water from the Vartry for the hard-water with which that city 
was formerly provided. Dr. Fox’s own experience leads him to 
the conclusion that a water of moderate hardness is preferable to 
either a very soft or a very hard water, and that a very soft 
water is preferable to a very hard one. 
On the pollution of rivers, Dr. Fox takes a view mid-way 
between the advocacy of negledt and the sensational and im- 
practicable policy of the defunCt Royal Rivers’ Pollution Com- 
mission. He quotes, approvingly, the diCtum of the Duke of 
Somerset — “ The foul matters encumbering streams may be got 
rid of, but the notion of their supplying water fit to drink must 
be altogether put aside.” For our own part we have very rarely 
found the water of a lowland river fit to drink, even in unin- 
habited and uncultivated districts. 
Concerning the degree in which various kinds of fish are 
affeCted by polluted waters there is much diversity of opinion. 
The author states in a note that “the gudgeon is said to be more 
liable than any other fish to be influenced deleteriously by impure 
water.” We have heard the same view expressed in other 
quarters. Yet the late Frank Buckland, in his “Natural History 
of British Fishes,” says that gudgeon are very fond of living in 
sewer water which would be immediately fatal to a trout or a 
salmon. Perhaps in reality the death of one species of fish, or 
the survival of another, depends more upon the kind than the 
mere quantity of the pollution. 
Dr. Fox denounces, very justly, the common practice of depo- 
siting solid refuse on the banks of rivers where they may be 
carried off by floods. To this pradice is due, to no small extent, 
