70 An Anidy.-^is of Filtered Water — Dodge, 



We have bo'eii repeatedly informed by sanitary authorities what 

 the consequences of drinking impure water may be —what they 

 undoubtedly have been in some localities in this country and in 

 Europe, and what they maij be here. Whatever our source of sup- 

 ply, river water, lake water, well water, cistern water, we know that 

 they are all liable to contamination with impurities of various 

 kinds, and that certain of these impurities, especially human 

 excreta, introduce into the water an element of danger and throw 

 upon those who partake of it a positive risk of contracting 

 disease. Now here in Minneapolis the greater number of us are 

 personally concerned with the character of the water of the river 

 as supplied by the city water works. We are for the most part 

 willing to admit that there are worse waters used than the river 

 water; but at the same time we are aware that the river water is not 

 up to tlie standard of purity which an intelligent and cleanly 

 community desires. Considering however, that it is the water with 

 which we are likely to be supplied for some time to come, we 

 are interested in any method by which this water can be made 

 better, by the destruction or removal of its impurities. I have been 

 giving some attention of late to the subject of the improvement of 

 water by filtration, and more particularly by domestic filtration. 

 At my residence we have been using for about a year a filter- 

 ing apparatus which we have applied to the purification of water 

 supplied by the city works, and, as I think, with satisfactory results. 

 (The construction of the apparatus was represented in a figure 

 on the blackboard.) 



The apparatus is of stone ware. A space holding about two 

 gallons is the receptacle into which is poured the water to be filter- 

 ed. The filtering medium is granuLited animal charcoal or bone- 

 black. A lower space holds the water after filtration delivering 

 it from a faucet. At one point is a sponge stuffed into a cavity as 

 rejtresented. The upper space is emptied and cleaned from time 

 to time, together with the sponge. It might surprise one not ac- 

 quainted with the subject to see the amount of dirt which deposits 

 itself in this space and in the sponge after a short time of use. 



In order to obtain some definite knowledge of the efficiency 

 of this filter, I drew a quantity of the filtered water into a well 

 cleaned bottle and took it to the laboratory for analysis. We did 

 not make a complete analysis, as I judged that unnecessary for my 

 purpose. But T submitted the water to two particular tests which 



