44° ' -Abbe fontana’s Account of Airs 
the reafon why fome kinds of water have a peculiar 
fharp tafte more than others ; and efpecially why fome 
of them precipitate the lime in lime water, rendering it 
a calcareous earth, and change the tindfure of turnfole 
into a red colour, as I have generally experienced with 
the well waters at Paris. We may alfo explain from 
hence, why fome kind of waters can diffolve iron, and 
keep it in diffolution without depofition ; whereas other 
hinds of water are incapable of doing it, at lead: do it 
much lefs than the pureft diftilled water. This is fooii 
difcovered by boiling the water, which will then depofit 
the iron which before was diffolved. 
It will be fufficient, for the prefent, to mention, that I 
have not only extracted from waters the different kinds 
of air they contained naturally, but have likewile made 
Various experiments upon waters deprived of air, which, 
being expofed, have again imbibed the atmofpherical 
air, as I hinted above. I have determined the quantity 
and quality of thofe airs. In general, I may fay, that 
diftilled water, deprived of air, imbibes again an equal 
quantity of air of the fame kind as that it had loft, and 
that in lefs than fifty days. Other kinds of water do the 
fame, but with this difference, viz. that the air they ab- 
forb, after being boiled, is better than that they have 
loft; and in this particular they come very near to the 
nature of diftilled water itfelff 
3 
If 
