i88o.] 
On Water and Air. 
57 
remove the lime from the water before the water can produce 
a lather and before the water can be used as a washing 
medium’. Well, now, the question is— How is this to be 
rendered soft ? Or, can this water be rendered soft on a 
large scale, or in an effectual way? Yes. 1 hat question 
has been answered in a most satisfactory manner by Dr. 
Clark of Aberdeen, and he has invented a process tor the 
softening of water, which, I think, is likely to come into 
great request in the future. At first sight it is a very extra- 
ordinary process; for what does Dr. Clark do ? He takes 
the lime from the water by putting more lime into it. Now 
that appears to be a strange assertion; but give me your 
attention, and there is not a boy here present that will not 
understand what I mean by that expression. 1 here [pointing 
to a vessel of hard water] is the lime intheform ofwhatwecall 
bicarbonate. There [referring to another vessel] is the lime, 
not united with carbonic acid at all, but as lime-watei. 
Suppose I pour a quantity of that lime-water upon that 
hard water/ There is nothing in Science which is more in- 
structive, or more interesting, or more inspiring, than the 
power of prevision,— the power of looking in advance, the 
power of allowing the mental eye, so to say, to go befoie 
the eye of the body. Now let us consider what is likely to 
occur if I pour this lime water into that hard water. Ihe 
lime in that lime-water will take away half the carbonic 
acid from the bicarbonate which is present in the haid 
Canterbury water. What is the consequence ? It will 
convert the bicarbonate into simple carbonate. \\ hat again 
is the consequence ? The simple carbonate, being insoluble 
in water, will appear as a' milky mass in the fluid. I should 
not be satisfied if every boy did not understand me in this 
most important process. Here we have the lime-watei. 
By adding this pure lime-water to the hard watei we take 
away half of that carbonic acid which enables the lime to 
be dissolved. Then we convert the soluble bicarbonate into 
the insoluble simple carbonate, and down it goes as a milky 
mass, and the change is shown in your presence in that way. 
There is the lime which has been separated from the haid 
water. This is precisely the process used by Mr. 
Homersham, at Canterbury, and at Caterham and else- 
where. I have gone specially to all those places to see 
the water softened, and a more beautiful process you 
could not imagine. Take the case of Canterbuiy. ou 
go there into a space which is perfectly clean, covered 
from all contact with the dust, or debris of the . an. 
You see there three great reservoirs, bach one of these 
