84 KANSAS ACADEMY OF SCIENCE. 
which are known to produce an injurious effect on the human system, or which 
are suspected with good reason, or on good authority, to produce such an effect. 
2. **The water should be. as far as practicable, free from all substances and 
from all associations which offend the general esthetic sense of the community, 
and thus affect the system through the imagination, even if there is good reason 
to suppose that it is within itself perfectly harmless.”’ 
Without doubt the best kind of water for drinking purposes is the moderately 
soft spring water, without any possibility of contamination by organic matter. | 
Unfortunately, however, such water is hardly ever found in sufficient quantities 
for the supply of large cities. 
WatTER ANALYSIS. 
Collection of Samples of Water.—The quantity of water which should be 
collected for analysis should not be less than a gallon, but in case of necessity a 
smaller amount will do. In collecting water, cleanliness should be insisted upon 
in all cases; the bottle or jar should be thoroughly washed out with weak sul- 
furic acid, then thoroughly rinsed with the same kind of water that is to be 
analyzed, and before collecting the water to be analyzed the collector should 
satisfy himself with the fact that there is no acidity left in the bottle from the 
acid used in cleaning it. After the bottle is sealed it should be immediately 
shipped to the analyst, in order that an examination be made of the substances 
that are liable to change by standing. 
Total Solids.—The determination of total solids is made by evaporating a 
certain quantity of water in a weighed platinum dish and heating to 130° C. 
After the water is all driven off, the residue is weighed with the dish; the differ- 
ence in weight of the dish and of the dish plus the residue gives the amount of 
total solids in the water. 
Chlorine.— Chlorine usually occurs in water in combination with sodium ; 
also, in small quantities with potassium, calcium, and magnesium. The amount 
of chlorine in water is not of a very great consequence, but the determination of 
chlorine is resorted to by chemists in order that they may be able to tell whether 
a certain water is contaminated with organic matter or not. 
The determination of chlorine is made by the use of a standardized solution 
of silver nitrate. 
There are some precautions to be guarded against in making this determina- 
tion: the chromate should be perfectly neutral and free from chlorides; the silver 
solution and the water should also be perfectly neutral. The reason that acidity 
should be guarded against is because chromate of silver is soluble in acids. 
A special method for the determination of the bases has been prepared by 
Prof. E. H. S. Bailey, and was used in these examinations. The method, with 
few additional suggestions obtained by experience in working with the above 
waters, is as follows: Determination of silica and insoluble residue, and of iron, 
aluminum, and phosphoric acid. 
Silica and Insoluble Residue.—Acidulate one liter of the water with HCl, 
evaporate to dryness on a water-bath, heat the residue to 110° C, digest the 
residue with HCl, sufficient quantity to moisten it well, add hot water, and filter; 
the residue upon the filter is dried, ignited, weighed and calculated as insoluble 
residue and silica. 
Tron, Aluminum, and Phosphoric Acid.— The filtrate from the preceding 
is treated with ammonium chloride and ammonium hydrate. After heating and 
allowing to settle, filter and wash. If the precipitate is very large it is redissolved 
in HCl and precipitated again with ammonium hydrate; the precipitate is then 
filtered out, dried, ignited and weighed as AlsOs, Fe2Os, and phosphoric acid. 
