DRmKIKQ-WATER AND SOME OF ITS IMPURI- 

 TIES. 



[A paper prepared by F. G. Ballart, and F. M. Comstock — Fellows of 

 Union College, and read by Prof. M. Perkins, before the Albany Institute 

 Oct. 2, 1877.] 



Much attention has been given of late to the drinking- 

 water supplied to cities. In England the subject has been 

 regarded as of so much importance that parliament has 

 appointed committees at various times to investigate the 

 subject. Their reports have done much to turn the pub- 

 lic attention in that direction. The question is now often 

 asked, " What constitutes good water ? " This may be 

 answered roughly by saying that good water must be 

 transparent, colorless, odorless even when a bottle half 

 filled with it, is placed in a warm place for several hours 

 and then shaken, and without taste except perhaps a slight 

 pungency due to oxygen or carbonic acid. But water 

 may comply with all these conditions and still be unsafe 

 to drink. It may contain injurious substances in suspen- 

 sion or solution, in sufficient quantities to render the 

 water bad, and still show no traces on a rough examina- 

 tion. These impurities can only be determined by a careful 

 analysis of the water. Let us consider a few of these im- 

 purities. 



Natural water often contains carbonate of lime, sulphate 

 of lime, sodium, magnesium, iron, etc., in solution. They 

 also contain phosphates, chlorides, and nitrates. All 

 natural waters, even rain water, contain the latter in cer- 

 tain proportions. Almost all of them contain the salts of 

 ammonia. Pond, lake, and river waters are generally 

 softer than spring water for the reason that while those 

 bodies of water receive the waters of springs, they also re- 

 ceive a considerable quantity which has simply run over 



