144 TRANSACTIONS iSqQ-'oO 



On the 13th October, of last year, I personally visited 43 

 wells, chiefly on farms, in the district between Kinburn and 

 Packenham, in the County of Lanark. This is an extensive clay 

 region, fairly level, except quite near Packenham, where the land 

 dips towards the Mississippi river. The Mississippi rises in a 

 series of small lakes, about 80 miles west of Packenham, in the 

 townships of Abingdon, Barrie and Clarendon, in Addington 

 County. These townships are very thinly settled, and the 

 whole course of the river is through a region but little affected 

 by human habitation. With the exception of the towns of Perth 

 and Almonte, it may be said to be quite as nature left it, and a 

 purer gathering ground could not be wished. This is proved by 

 the fact that a sample of the river water taken at Packenham 

 gave only two parts of chlorine per million. No doubt, this 

 small content of chlorine is chiefly derived from sewage for, 

 although the organic matter of sewage may change by oxidation 

 as already explained, the chlorine remains, to tell the tale of past 

 sewage pollution. In the case before us, the amount is too small 

 to give any concern for the purity of the river water — No doubt 

 there are points on the river, (e. g. just below the town of. 

 Perth,) where locally, a higher chlorine figure would be found, 

 pointing to local and serious sewage contamination. But the 

 volume of the river is so large, that by the time the sewage has 

 distributed itself uniformly throughout it, the figure 2 per million, 

 for chlorine, has been reached, and the organic impurities have 

 been fully oxidized. 



The following numbers were obtained for seven wells in the 

 region referred to ; the wells having a depth of less than 10 feet, 

 and being of the kind called surface wells. 



Why are these numbers so much higher than the river water 

 gave ? There is but one answer : — the wells are dug in soil which 

 is more or less saturated with sewage. Not one of these wells, so 

 far as I could learn, was protected by a clay backing, (see Fig. 



