68 



All the waters considered so far are chalky waters, and by 

 virtue of their containing chalk they possess the power of neutral- 

 ising a definite quantity of acid, which serves as a measure of 

 the temporary hardness or of the potential alkalinity of the water. 

 For instance, the average of 21 such determinations yields the 

 figure 14.7 as representing the alkalinity of our water measured 

 as parts of chalk in 100,000 parts of water, while for the 

 Poole water the value is 19.3, and for the West Hants Company's 

 water 19.4. Water from peat, however, contains organic acids, 

 and so far from being able to neutralise acid, it can itself be 

 neutralised by a solution of soda and its acidity so determined. 

 As an example, a peaty surface water from Hern contained acid 

 equivalent to one part of acetic acid in 100,000 of water, another 

 from a bog spring there contained nearly 4 parts. Both were 

 very soft, and of course any hardness would be permanent and 

 certainly not due to calcium carbonate when the water is decidedly 

 acid. The consideration of the properties of these waters is a 

 matter of vital importance. Such waters are nothing less than 

 dilute acids and passing through Lead pipes would dissolve a 

 considerable quantity of the metal and become highly dangerous 

 although probably quite wholesome if taken at the source. 



Many people believe that the salts in hard waters have a 

 decidedly injurious effect on the health, and not a few enthusiastic 

 dietetists distil every drop of water they drink, while others seek 

 hard waters believing that the salts are beneficial and necessary. 

 However, if we consult the best modern authorities, we shall 

 find the opinion steadily gaining ground that the quantity and 

 nature of the salts taken and the length of the period over which 

 the* consumption is spread makes it a matter of indifference to 

 the health whether one drinks hard or soft water. The total 

 solid residue from the evaporation of 250 c.c. of our water — an 

 average example of a water — leaves but a filmy deposit over the 

 bottom of the dish, 65 milligrams or one grain in weight. Cal- 

 culating on the basis that a person consumes 2^ pints of the water 

 daily in various ways, the salts so taken in one year amount to 

 4f ounces Av. 



The task of taking a water sample for analysis is one that 

 may fall to anyone, but few T appear to know the correct procedure 

 in collecting a sample of water. The most important point is to 

 see that the bottle is clean beyond all suspicion. In the analysis 

 of a water the first thing done is to look at the water, the second 

 is to smell it, and on endeavouring to perform the second test I 

 have known samples to smell of vinegar, whiskv, and of coffee 

 essence while the inefficient washing usually has left the label 

 on the bottle to confront one and confirm 'the evidence of the 

 sense of smell. Samples in medicine bottles rarely fail to possess 

 one of the smells characteristic of phvsic. 



So the bottle should be scrupulously clean and should possess 

 a glass stopper, but if this latter is impossible, the cork used 



