AN EXAMINATION OF THE WATERS OF DARTMOOR AND EXMOOR. 8 7 AN EXAMINATION OF THE WATERS OF the river has received the Lumbourne brook. Sur- DARTMOOR AND EXMOOR, rounding formation, Devonian slate, greenstone, granite, and carboniferous shale. The sewage of .AND OF THE DEVONSHIRE RIVERS--DAR'I:, TEIGN, Tavistock irrigates meadows by the river side, the TAW, OKEMENT, TAVY, PLYM, EXE, AND LYN. last of which is about a mile above the point where By J. H. GARRZTT, M.D., L.S.SC.. etc. last sample was taken. The analysis proves that (Continued from .page I3). the organic matter of the sewage is destroyed. 5" The Tavy.~Rising in an exactly similar 6. The Plym.--A sample of water was taken manner to the Dart, it flows to the south-west. At from the Plym, near Bickleigh Station, about seven ~ts head, in places where the black, peaty material miles above the tidal water. The river has only is entirely washed away, a china clay or kaolin is touched the granitic and Devonian rocks. The exposed, which gives up a little free alkali to the neighbouring land and banks of the stream are water. About a furlong from where the water first sandy at this point. The china clay is worked on begins to run, its reaction is alkaline. In the first the Plym in several places. two or three miles of its course the Tavy receives The geology of Exmoor differs from that of Dart- the waters of several iron springs, which generally moor. In place of the granite we get sandstones have the odour of sulphuretted hydrogen, are and slates of the Devonian system. These give up strongly alkaline, and deposit iron oxide upon the an extremely small amount of soluble matter, so straws, etc., at the bottom of the stream, and also that the surface waters are characterised by a soft- lower down give the granite boulders a red tinge. ness and purity even greater than those of Dart- Four samples were taken. No. I, at head of Tavy, moor. During a walk across Exmoor the reaction ioo yards from where water first begins to run. of the waters was tested in numerous places. No. 2, at Tavy Cleave, surrounding formation Where stagnant upon peat it is everywhere acid, granite. No. 3, near Mr. Radford's house, Mount and small peaty pools and puddles are of frequent Tavy, three-quarters of a mile above Tavistock. occurrence. The waters of several springs that No. 4, at a point two miles below Tavistock, after were tested proved to be neutral or barely alkaline. ANALYSKS OF THE WA'IERS OF THE RIVER TAVY, AT DIFFERKNT POINTS IN ITS COUSSE, AND AN ANALYSIS OF THE ~'¢~'ATER OF THE PLYM. z.--: o .3 u. ~Z %: ' ,o i,= Ix';~ o i :2- n Grains per Gallon, In In Partsper blillion. Sample I. i deg. None From head May May Faintly Brown ; clear ; Earthy. 3 o '6 "or 'oo 3'o "oo "07 I'49 or:mere ot Tavy. j I6th 18th Acid. slight deposit. trace. Sample II. i Odour no~e ; taste fresh, None F~om Tavy, AprillApd~'1'~ Alka- Brownno depcsit. ; clear ; 5 o '6 "ol o5 I '4 "oo "07 I'25 r~rmere t at Tavy 2oth 21st line. b u t slightly trace. Cleave. i I i brooky. .~.From Tavy,* I April April• i Alka- Sliehtly brown; 0dour none ; taste unplea- 5"0 "O6 2 "0 "00 •02 I "I0 None. above Tavi-ilTth]ISth I line. turbid ; with stock. deposit. sant ; earthy. Sample Iv. Odour none ; t~ From Tavy, iAp~ilAprll Slightly bTown: Atka- clear ; sight taste slightly 8o "0 "I0 4"o "o2 "o5 x'4~ None. o. below Tavi- i 17th I8thl line. blocky ; fresh. i ~tock. I i deposit. E Sample v, Mlsa~l Slightly brown; Odnur none; From Plym, Mayl Alka- clear ; sqght ,aste slightly 4.0 '8 •oi I 8 "O2 06 "7i ~None. at Bickleigh,, 18th' line. deposit. brooky. !t 88 AN EXAMINATION OF THE WATERS OF DARTMOOR AND EXMOOR. These springs are very clear, pure, and tasteless. near Dulverton, 5 ° yards below the juhction with The running waters are everywhere alkaline, even the river Bade. The river is here just off the those of the smallest rills having this reaction in Devonian, and, before the next sample is taken, dry weather. The alkalinity, however, is very flows over four or five miles of carboniferous, and slight. Whence it is derived is an open question. about one mile of new red sandstone rocks. No. 4, The small pieces of sandstone commonly found at at a point distant about one mile above Tiverton. the bottom of the streams in this district, when No. 5 is from a small tributary of the Exe that rubbed with a naturally acid water do not appear passes Yeoford station, at which point the sample to have power of neutralizing the acid. It is pos- was taken. A considerable portion of its water is sible, however, that this first alkalinity is due to an drained from the new red sandstone rocks and organic base or ammonia rather than to one of a soils, and the analysis may be contrasted with the fixed and inorganic nature. waters of the Exe before it reaches the new red The river Exe rises on Exmoor about six miles formation. south of Lynmouth, and takes an easterly and The Lyn rises on the moor in two distinct southward course. Four samples were taken from streams which join at Lynmouth. It touches it. No. i, about half a mile from its actual source, none but Devonian rocks. A single sample was three or four miles to the north of Simonsbath ; taken from the East Lyn, about two miles from No. 2, at Exford, just above the village; No. 3, Lynmouth and 50 yards below Watersmeet, This ANALYSES OF THE WATERS OF THR RIVFI~ EXE, AT DIFFERENT POINTS IN ITS COURSB, ANn AN ANALYSIS OF THE WATI~R OF THE LYN. i In G'ains per Gal on In In Parts per Million. Sample I, leg. From Exe; n ; very Odour none ; A near its ; no de- taste slightly Y5 I 01o, oo •oo -03 x'5 i large trac. source. brooky. Samfle II. tly brown; Odour none ; I "~O [ -- Nor e From Exe, at ; slight taste veryt6'o "O2 "OO 20 •o2 "79 ,rme~e Exlord. sit. slight. trace. slight Sami)le hi. None Tn tint ; 1 From Exe Odour none;I 5° tly turbid; •oo I x'8 or •,:,, near Dulver- ta,~te brooky. I •co "04 "99 mere ton. slight de i. trace. i SampleIV. slight Odour none ; From Exe, m tint ; taste very above Tiver. tly turbid ; little, not un- 4"5 "oo I 3"o oo "o6 1"o None tOn. tt deposit. pleasant. I SamgMev. Fr~ m small tributary o~ t brown Odour none ; Exe on Ntw ; ulrb~d ; taste good. [I2 5 uo I 6-8 •oo .i2 Trace. Red Sand- t deposit. stone, at f Yeotord. 1 ] Sam¢le vI. From Lyn, z t brown Oclour none ; t ; clear ; taste slightly 4"5 i Slight miles from •o2 "oo 2" 3 "OI I .09 I'll F, ace. rnouth. t depo.~m brooky. [ AN EXAMINATION OF THE WATERS OF DARTMOOR AND EXMOOR. 89 proved on analysis to be rather less pure than the days, when a large deposit had collected at the waters of the upper Exe. bottom of the glass, the lead in it, together with Notice was taken of the action upon lead of the little in solution and suspension, was equiva- several of these waters by allowing two pieces of lent to 21 grains Pb per gallon. clean sheet lead, each z in. square, to stand in 4-Water from the Dart at Staverton. Its five ounces of the water contained in a tumbler alkalinity had been increased in the neighbourhood glass. In this way ot experimenting the result of of Buckfastleigh, where it passes over a bed of the action is seen. Those who prefer to put the limestone, and receives drainage from the surround- water into a lead pipe cannot see what is going on, ing limestone district. There was a tendency for and must sometimes unknowingly leave the lead action on lead to commence--the lead being clean salt that has been formed adhering to the inner --but this was quickly cut short. After twenty- surface of the pipe, whilst they calculate the four hours the few curdy floccuta that had been amount of action that has taken place by the lead formed and deposited contained lead equivalent to that remains dissolved in the water. The com- •05 grains Pb per gallon. parative softness of these waters allows of some considerable action on lead in almost every case. A VILLAGE HOUSE, NEW GUINEA.--The tribe When a perfectly clean lead surface and a volume of Odagesitia (New Guinea), numbering several of water are placed together in the above propor- hundreds, live all together in one house. This tions, the carbonate in the water is rarely sufficient house is stated to be scrupulously clean, 520 to coat the lead and so prevent action. The acid feet long and 3 ° feet wide.--Annual ColoMal waters from the stagnant peat pools have power of Rezborts, No. 6, British New Guinea. actually dissolving lead. The amount of lead EFFECTS OF CHOLERA ON TRADE.--The returns dtssdved by the numerous samples of water re- of trade at Atexandretta, the port ot Aleppo (189o) moved from the rivers, etc., which had a faintly show a diminution in value of .£294,597 as alkaline reaction, was so small as to be hardly worthy regards exports, and of £48,15 S as regards imports, of mention, but their action on lead was frequently when compared with i889.