1886.] NEW YORK ACADEMY OF SCIENCES. 53 



such aluminated water. Oa the contrary, its use, under the 

 circumstances mentioned, is highly beneficial. It removes the 

 insoluble alumina compounds originally present in the water. 

 The insoluble coagulum or clot thus formed carries down with 

 it the products of putrescent decomposition, which are always 

 present in natural waters, except such as come from deep-seated 

 sources like wells and springs. And at the same time there are 

 precipitated in this coagulum the microbes, or so-called disease 

 germs. In fact, there is no process so practical and effectual for 

 removing these germs and putrescences as the use 0/ alwn in small 

 quantities followed by filtration. Long-continued boiling 

 destroys them, but it is costly and impracticable. It renders 

 the water bad-tasting, destroys its liveliness by expelling the dis- 

 solved gases, and makes the water unfit for domestic use. 

 Freezing leaves much of the organic matters in the water, de- 

 stroys only a portion of the germs, and is impracticable. But 

 by the use of the above means, river waters which were originally 

 yellow and turbid from the presence of mud and finely divided 

 silt, and disgusting from sewage and organic filth, have been 

 rendered clear, safe, and palatable. 



For softening hqrd water, the precipitant used is lime, the 

 lime carbonate thrown down being removed by filtration. Esti- 

 mating the hardness in degrees, and taking one degree as that 

 equivalent to the hardening produced by one grain of lime car- 

 bonate dissolved in one gallon of water, the hardness has been suc- 

 cessfully reduced from twenty-six degrees to three degrees, or from 

 very hard to soft water. Not only is the water thereby rendered 

 fit for use in boilers and in washing, but it is more wholesome. 

 Soft water in itself is more wholesome than hard, and moreover, 

 in the process of softening in this manner, the coagulum of lime 

 carbonate carries down with it the micro-organisms of disease. 



In the way of overcoming difficulties this result, striking as it 

 is, is not so significant to the chemist as the removal of the deep 

 coffee-colored dye imparted to the water by juniper swamps. I 

 give here the analysis of such a water from a southern swamp, 

 which by the use of alum and lime, and subsequent filtration, 

 was changed from a deep yellow, peaty tasting and boiler corrod- 

 ing water, to a perfectly colorless, limpid, sweet water. 



composition of "water from juniper swamps. 



Parts per 100,000. 



Free ammonia, 0.0095 



Albuminoid ammonia, 0.0335 

 Oxygen required to oxidize 



organic substances, 4.05 



