60 KEPORT— 1869. 



The fibsoi'ption-bands fiu'uisli a ready test for bile iu liquids, such as water or 

 urine, which have no absorption -hands of their own. With a column of liquid 

 2i inches long, the presence of bile was in this way discovered, when diluted 100 

 times, and with a column 8 inches long, when the dilution was carried fom- times 

 further. An estimate of its amount may also be made, and its fluctuations in 

 disease observed from day to day. 



The Water SuppVies of Ph/mouth, Dcvonport, Exeter, and St. Thomas. 

 Bj Hexry K. Bajibee, F.C'.S. 



The water supplied to the town of Plymouth is taken near Sheepstor, from the 

 River Meavy, which receives its water" from the granite-hills iu the neighbour- 

 hood, and has a drainage area of about 4000 acres. 



The water is conducted from the river by means of an open leat as far as 

 Knaekerskuowle, a distance of about 12 miles, from thence the water for do- 

 mestic use is carried through iron pipes of 24 inches and 12 inches diameter, a 

 further distance of about three miles into reservoirs, from whence it is distributed 

 to the different parts of the town. 



The surplus water is carried from Knackerslniowle by the old leat around a 

 distance of about 10 miles, to supply several mills, and is then delivered into the 

 Gre.at Western Docks at Milbay, The supply of the water is in the hands of the 

 Corporation. 



Analyses of samples of the water, taken at the commencement of the leat at 

 Sheepstor, and in Plymouth, gave the following results. It was perfectly clear, 

 transparent, and colourless, and contained in an imperial gallon :— 



At Sheepstor. In Plymouth. 

 grains. grains. 



Inorganic matter 2-38 2-61) 



Orgiinic and volatile matter 0'57 0'54 



Total solid matter 2-95 3^ 



Chloride of sodium 1-25 1-29 



Ammonia 00045 001 



Iv itrates none. slight trace. 



Hardness before boiling 0°'61 0^-7o 



The inorganic constituents were principally chloride of sodium and sulphate of 

 calcium. 



These samples were taken after a continuance of drv' weather, on jVugust 5, 

 1869, It is very good water, and for manufticturing, cooking, and washing pur- 

 poses, its extreme softness is a pTeat advantage : but it acts rapidly on the iron 

 pipes, corroding them considerably, thereby diminishing their internal diameter, 

 so that now all the pipes are coated with asphalte before being fixed in their 

 places. 



Devonport Supply. — The water supplied to Devonport is taken from streams 

 near the source of the River Dart, on Dai'tmoor, including one stream which 

 would be much better excluded ; for, as its name (Blackwater or Blackabrook) indi- 

 cates, its water is highly colom-ed \sith peat, and colours the water of the Devon- 

 port leat. 



The water is carried nearly all the way, a distance of 34 miles, in an open leat. 

 Some portion of the water, however, is detained at Knaekerskuowle, and from 

 thence is delivered through iron pipes into a reservoir at Stoke, to supply the 

 higher levels, but the largest portion is delivered into Devonport from the leat 

 direct. 



I took a sample of the water from the leat at Downsland Barn, and also a 

 sample in Devonport, as supplied to the Company's own offices. On analj^sis the 

 samples gave the following results. 



The water was clear and transparent, but had a brown colour of peat, the sample 



