THE DOMESTIC WATER FILTER. 



By the Hon. W. F. TAYLOR, M.D., M.L.C., M.R.C.S. 



Dip. Public Health. 



[Read before the Royal Society of Qiieendand, April 20, 1895. 



The filter being an article of pretty general use in this com- 

 munity, it is a matter of importance to ascertain to what extent 

 the various filters sold are reliable as a means of purifying the 

 water which passes through them. The source of the water 

 supply is the rain which falls either on the roofs of buildings, 

 and is collected and stored in tanks, or on the catchment areas 

 of our reservoirs, and those of the Upper Brisbane river and its 

 tributaries, well water being used in very few instances, if any. 

 In the case of the tank water, it is obvious that unless some 

 special means are provided for excluding the first washings from 

 the roofs, it must be contaminated with the dust and leaves 

 which have collected on them since the previous rainfall, and 

 consequently the tank in which the water is stored becomes the 

 receptacle for decaying organic matter, and the storage and 

 propagation of bacterial organisms. However, as all suspended 

 matters fall to the bottom, and the tap being inserted some 

 inches above it, the water drawn from the tank is as a rule 

 clear and palatable, if we except the metallic taste usually 

 present in all water gathered from galvanised iron roofs and 

 stored in galvanised iron tanks, and is consequently, in the 

 majority of cases, drunk without being filtered. But many 

 householders, under the impression that although the water 

 may be clear, it must, from the manner in which it has been 

 collected, contain impurities not visible to the naked eye, and 

 therefore ought to be filtered before being drunk, or boiled and 



