TRANSACTIONS OF THE SECTION'S. 61 



taken at Devonport being the least coloured of tlio two. It contained in an imperial 

 p-allon : — ■ 



At Downslaiul Barn. In Devonport. 

 grain.i. grains. 



Inorganic matter '2'5d ^ 2'Sij 



Organic and volatile matter 1'4G 0'58 



Total solid matter 40.5 2-94 



Chloride of sodium 1-20 1-55 



Ammonia 0004 001 



A'itrates none. slight trace. 



Hardness before boiling 0°-9 1°"0 



The inorganic constituents were the same as in the Plymouth_-water,_but the 

 sample taken in Devonport contained a quarter of a grain of oxide of iron per 

 gallon, which had been dissolved as the water lay in the pipes ;_ the action of the 

 water on the pipes also removed, as usual, a considerable quantity of the organic 

 matter. 



This water, like the Plymouth water, is exceedingly soft, and on this account is 

 admirably adapted for culinary and manufacturing pui-poses ; but from the pre- 

 sence of "the colouring-matter," it is not so agreeable for drinking purposes as the 

 Plymouth water. 



These very soft waters always rapidly corrode the iron pipes, not so mucli 

 by deposition from the water, as by converting the iron of the pipes into o.iide 

 of iron, pipes of 12 inches diameter becoming, after a few years, reduced to 10 

 inches in diameter. These waters also act on freshly cut lead. 



Rveter Stipphj. — Tlie water used lor the supply of Exeter is taken from the river 

 Exe, at Upton Pines, about two miles and a half above Exeter. The water is 

 pumped from there to the reservoirs and filter-beds at the back of the County 

 Prison in Exeter, from whence it is distributed to the town, but the water used to 

 supply the higher levels is frequently pumped directly from the river to the 

 houses, without filtration. I took a sample of the water at the house of PI. S. 

 Ellis, Esq., the present Mayor of Exeter, from the tap as it was running from 

 the main into his cistern; the water was red with rust of iron, and depo.?ited a 

 considerable quantity of earthy matter on standing. 



I also afterwards obtained a sample of the water of the Exe, above the entrance 

 of the river Culm, from the spot whence the future supply is to be taken. 



Analyses of these two samples gave the following results. 



After all sedimentary matter had been allowed to deposit, the clear water was 

 poiured oft^ and contained, in an imperial gallon : — 



In Exeter. Future supply, 

 grains. grains. 



Inorganic matter 11-48 6-6.3 



Organic and volatile matter 0T6 1 -00 



Total solid matter 11-64 7-63 



Chloride of sodium 2-15 1-75 



Ammonia 0-005 0-006 



Nitrates a trace. a trace. 



o o 



Hardness before boiling 7 GO 4-57 



„ after „ 2-27 2-72 



The'inorganic constituents were carbonate and sulphate of calcium, carbonate of 

 magnesium, and chloride of sodium 



In the case of the sample taken in Exeter, a considerable quantity of the organic 

 matter originally present in the water had been removed by the action of the 

 water on the iron pipes. 



This is a good water, and that taken from the Exe, above the entrance of the 

 river Culm, is all that can be desired for a domestic and general supply. 



