292 Remarks tending to facilitate the Analysts 
bleaching of linen and cotton, and in other operations where 
cleanliness is the object in view. Many of the manufactories are 
materially interested likewise in the qualities of water, and in the 
methods of rendering it subservient to their exigencies when it 
happens to be presented to them in an obnoxious form. On all 
these accounts I thought it might be of some service to offer a few 
remarks on the subject, which, perhaps, may benefit those who 
have not made the science of chemistry a peculiar object of study. 
Most writers consider the analysis of waters as a problem re- 
quiring great skill and acquaintance with chemistry; but the 
modern improvements in that science have rendered it much less 
so than formerly. It is true, that the variety of elements some- 
times found in water, and the extremely small quantities of them, 
are discouraging circumstances when the object of analysis is to 
ascertain both the kind and quantity of these foreign elements. 
They may both, however, be investigated without much labour, 
when proper means are used ; and, perhaps, a little practice may 
render a person qualified to undertake the task, who is no great 
adept in chemical science in general. 
Most spring water that is obtained by sinking some depth into 
the earth, contains lime held in solution by some one or more 
acids, particularly the carbonic and sulphuric acids. 
It is to these salts, the carbonate and sulphate of lime princi- 
pally, that spring water owes its quality of hardness, as it is 
called ; a very singular and astonishing quality, when it is con- 
sidered as produced by so extremely small a portion of the earthy 
salt. The other earthy} salts, or those of magnesia, barytes, 
and alumine, produce the same effect nearly, but they are rarely 
met with, compared with those of lime. 
When any earthy salt is dissolved in pure distilled or rain 
water, it imcreases the specific gravity of the water; but, in the 
instance of spring water in general, this test is rendered of little 
use, because the increase of sp. gr. is so small as almost to elude 
the nicest instrument that can be made. I have, however, an 
instrument, made by an artist in this town, which is nothing 
more than the common glass hydrometer, but with an unusually 
fine small stem, that shows the superior gravity of spring water. 
It cannot, indeed, be brought in competition with other metheds 
for ascertaining the relative hardness of spring water, but it is a 
most useful instrument in other departments of chemical inves- 
tigation, particularly in determining minute portions of residual 
salt after precipitations *. It may well be conceived, that the 
* The scale of the hydrometer is one inch and a half long, and it is divided 
into 25°, each degree corresponding nearly to “0004 ; the difference between 
distilled water and eommon spring water is usually about 1° on the instru- 
re 3; and that between distilled or rain water and the strongest lime water 
is 4°. sp. 
