DETERMINATION OF ODOR 
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OpoR AND TASTE 
Odor and taste are probably the most important of any of the 
organo-leptic tests. A chemically pure water is odorless and tasteless. 
It also has a decidedly insipid flavor as may be determined by tasting 
distilled water. Most people demand a water with some taste. 
Determination of Odor. Whipple’s (1899) method 1s the standard. 
The quality of the odor may be expressed in the following terms: 
a. aromatic m. moldy 
C. free chlorine M. musty 
d. disagreeable P. peaty 
f. fishy s. swectish 
g. grassy S. hydrogen sulphicae 
v. vegetable 
The intensity of the odor may be expressed in numerical terms as 
follows: 
Numerical 
Value Term Approximate Definition. 
0 None No odor perceptible. 
1 Very faint An odor that would not be ordinanly detected by the 
average consumer, but that could be detected in 
the laboratory by an experienced observer. 
2 Faint An odor that the consumer might detect if his atten- 
tion were called to it, but that would not otherwise 
attract attention. 
3 Distinct An odor that would be readily detected and that 
might cause the water to be regarded with disfavor. 
4 Decided An odor that would force itself upon the attention 
and that might make the water unpalatable. 
5 Very strong | An odor of such intensity that the water would be 
absolutely unfit to drmk. (A term to be used only 
im extreme cases.) 
RESIDUE 
The residue is obtained by evaporating a known amount of the water 
to dryness. The amount of the residue depends upon the character of 
the water. One having a high content of carbon dioxide will dissolve 
much inorganic matter. The relation of the residue to health depends 
upon their character. Certain salts cause decided physiological dis- 
turbances in some individuals which accounts for the therapeutic value 
of certain natural waters. 
