NOTICES OF PAPERS CONTAINED IN British and Foreign Journals. On the Constitution of Salts. BY Alexander W. Williamson,* There is strong reason for believing that all questions concerning the chemical constitution of matter will be most tangible when con- sidered from the point of view of the constitution of salts which are the groups whose arrangement and transformations are most susceptible of being ascertained experimentally. The elementary bodies themselves have been now shown? to obey a certain force of combination between their particles analogous though generally inferior to that which holds together the constituents of a salt; and any general conclusions which may be established for salts will therefore extend to them. Now to have clear and connected notions of any order of phenomena it is necessary to be able to judge of the various cases belonging to it from the same point of view or in other words to have a uniform standard of comparison.Thus if the value of mechanical forces had to be compared it would evi- dently not do to measure the one in pounds and the other in kilo- grammes unless the relative value of these units were known i.e. unless the statement made in the one could be reduced to its equi- valent in the other. Such unity has as yet been but little attended to by the majority of chemists; and the different branches of the science remaining disconnected their efforts have been directed to es-tablish details rather than general laws. Thanks to the numerous facts which have been thus established it is now possible and even neces- sary to do something more.The researches of Mhl. Laurent and Gerhardt have been mainly directed to this point and it is well known how fruitful their conclusions have already proved. The following remarks have an intimate connection with those conclusions and will hardly be intelligible without a knowledge of them. * Chern. Gaz. 1851) the entire paper). -f See Mr. Brodie’s research ‘‘On the Condition of certain Elements at the moment of Chemical Change.” DR. WILLIAMSON ON THE CONSTITUTION OF SALTS 351. We are all agreed that chemistry is concerned with the material process of the transformations and changes which matter undergoes and that the study of the properties of matter in themselves as long as they undergo no change belongs to physics.The chemical for-muliz by which we describe more briefly than by words the trans- formations supposed or known to take place have as yet answered that purpose very imperfectly and have presented great irregularity of method; for although generally denoting a certain arrangement of atoms or at least certain differences of arrangement they are some- times used to describe the origin of a compound or its decom- positions without forming any other representation of its actual constitution than what may be contained in such a statement. M. Gerhardt has in a recent memoir published conjointly with M.Chancel given considerable development to this latter method; and his so-called synoptic formuliz will I think he found very sug- gestive and useful expressions.But formulz may be used in an entirely different and yet perfectly definite manner and the use of two distinct points of view will perhaps not be unserviceable. They may be used' as an actual image of what we rationally suppose to be the arrangement of constituent atoms in a compound as an orrery is an image of what we conclude to be the arrangement of our planetary system ;and decompositions may be actually effected between them by the exchange of a molecule in one group for a molecule in another. Gerhardt's formula for sulphate of soda (if he extends his principles to inorganic chemistry) would be sulphuric acid plus soda minus water. This no doubt gives a possible origin of the salt but by no means a possible decomposition ;in other instances the inverse would be the case.Rut the tern1 sulphate of soda does not mean a body formed in any one particular way; it is equally applicable to the product of the action of sulphuric acid on chloride of sodium or on carbonate of soda or even to the product of the action of soda on sulphate of iron. The written name should be made to represent what we conceive a compound lo be and should be such that it might be formed by any one of the various processes by which the compound may be prepared. Sulphate of soda is a physical term and corre- sponds to purely physical propcrtics ; for the substance described by it does not by itself undergo any change but only when acted upon by certain foreign substances under suitable circumstances.When we study a molecule by itself we study it physically; chemistry considers the chclnge effected by its reaction upon another molecule and has to describe the process by which that change is effected. A chemical decomposition should therefore be represented by the juxtaposition of the formula? of the reacting substances and by effecting in these forrnuke the change which takes place in the mixture. The adoptiou of such a method will of course necessitate the adoption of types from which by the replacement of certain ele- 352 DR. WILLIAMSON ON THE CONSTITUTION OF SALTS. nients or molecules we can deduce the constitution of more and more complex groups. I believe that throughout inorganic che-mistry and for the best known organic conipounds one single type will be found sufficient; it is that of water represented as containing 2 atoms of hydrogen to f of oxygen tbus EO.In many cases a multiple of this formula must be used and we shall presently see how we thereby get an explanation of the difference between mono- basic and bibasic acids &c. I will here give a few examples of the application of this universal type to the formulE of common substances. The experiments of M. Chancel agreeing in result with my own have clearly proved that the numerous family designated as hydrated oxides are not formed by the juxtaposition of an atom of water with an atom of metallic oxide e.g. K,O+H,O but that the equivalent of the molecule is half of that quantity naniely ZO; they are not com- pounds of water but products of Substitution in water.This fact is as applicable to the compound as to the simple radicals ;and alcohols which are truly hydrated oxides must be considered as products of substitution of the compound radicals methyl CH3; ethyl C,H5; amyl capryl, wr fi water> CH O C,H €5,; C C H, (Bouis) &c. for half the hydrogen 0 &c. The anhydrous oxides of metals have Of -... both atoms of hydrogen replaced by the metal as EO in the same way as comr~ion ether and its homologues have ethyl in place of both the atoms of hydrogen. In extending this mode of notation to salts and compound ethers we must of course keep carefully in view the capacity of saturation of their acids writing the nionobasic acids such as hydrochloric nitric acetic &c.at half their usual equivalents CIW NO H C,H,O, but retaining the customary atomic weights of the bibasic acids as sulphuric carbonic oxalic &c. As alcohol is truly an acid in its reaction we must of course con-sider the potassium-alcohol ' E5 0 as its salt though alkaline in its reactions. We only need to replace 2 atoms of hydrogen in the radical of this salt by oxygen to have a compound of which the saline character is acknowledged viz. acetate of potash ('2 2 0. The most simple mannwsf representing the rational constitution of this compound is to state that it contains in lieu of the ethyl of the former salt an oxygen-ethyl C H 0 which we may term othyl.If the 2 atoms of hydrogen in water were replaced by this othyl we should have anhydrous acetic acid ('2 H3 O)O. In fact the so-called (C H 0) DR. WlLLIAMSON ON THE CONSTITUTION OF SALTS. 353 anhydrous acids are nothing else than the ethers of the hydrated acids. Again by replacing the potassium in the ethylate '2 g5 0 by its equivalent of cyanogen (which may be effected by the action of iodide of cyanogen) we obtain a compound of the composition ','5 0, (NC) that is cyanic ether. It is well known from Wurtz's elegant researches that by acting upon this body by hydrate of potash we obtain carbonate of potash and ethylamine; that is in the place of carbonic oxide in the cyanate we get hydrogen and reciprocally with the hydrate.Now can this exchange be represented riiorc simply than by stating the fact that in the following diagram the bydroeen of the 2 atoms of hydrate of potash changes places with the carbonic oxide of the cyanate ?-K2 K2 02 02 1 atom of carbonic oxide is here equivalent to 2atoms of hydrogen and by replacing them holds together the 2 atoms of hydrate in which they were contained thus necessarily forming a bibasic com- pound (io) 0, carbonate of potash. 2 If we knew how to form the compound COC1 i,e. phosgene with half as much chlorine it would be easy by its reaction upon our ethylate of potassium to prepare oxalic ether (and chloride of potassium). Oxalic ether is therefore alcohol in which the basic hydrogen is replaced by carbonic oxide with twioe the equivalent that it possesses in the carbonates; and the best evidence of the truth of this view is afforded by M.Dumas' elegant reaction of ammonia upon the ether forming the compound of amidogen with carbonic oxide (oxamide) and replacing the carbonic oxide by hydrogen reproducing alcohol :-Sulphurous acid is another radical capable of replacing hydrogen ; and the sulphates are thus reduced to our type being bibasic for the same reason as the carbonates. We have thus for sul~huric acid 20,; acid sulphate of potash k%0,; neutral sulihate 354 DR. WlLLIA1\ISON ON THE COXSTITUTION OF SALTS. There are various reactions both of formation and decompositioii of sulphates which bear out this view ; for instance chlorosulphuric acid SO CI, in contact with 2 atoms of water at once replaces half so the hydrogen in both by SO, forming B(C1H) and H,2 0,.And again the difference of the action of zinc upon sulphuric acid according to the concentration evolving. at one time hydrogen at another sul- phurous acid affords evidence that the sulphurous acid is contained in a manner similar to the hydrogen. Nitric acid presents according to the usual view of its constitu- tion a singular difference between its behaviour to organic and tG inorganic compounds; but this difference is owing merely to the error of that view. We are taught that nitric acid combines directly with mineral bases ; but when reacting upon hydrogen compounds it has a powerful tendency to replace hydrogen by hyponitric acid.Now if hydrogen in organic compounds without number be re-placeable by hyponitric. acid why should not also the hydrogen in hvdrate of potash be so replaceable ? The moduct of that substitution {odd be ni very improbible body only lommon nitrate of potash, (Npo. One more example and I have done. Chlorine is well known to react upon hydrogen-compounds by replacing hydrogen by chlorine with formation of hydrochloric acid. So it is also when it reacts upon water in presence of bascs 0 (hydrated hypochlorous acid} am! ClH being formed. In like manner we have for the series of oxygen-acids of this radical the formulE ('f' 0 chlorous acid; ('z2)0,chloric acid ; ('23) 0 perchloric acid. In order to accomplish what I above alluded to as a desideratnm for the explanation of chewical reactions namely effecting between the formulz of the reagents the interchange supposcd to take place in the mixture I make use of a kind of movable diagram in which the symbols of those atoms which have to change places are placed upon the extremities of a piece of card so fixed by a pivot to the board that by turning round 180° it reverses the positions of the exchanging atoms.* I would not have brought before the public considerations so purely theoretical as the above had I not found the conclusions of consider- able practical utility in the study of reactions.In the theory of types we owe to M Dumas an idea which has already been the vehicle of many an important discovery in science and which is undoubtedly destined to receive still inore general application.* Seep. 231. ON A CLASS OF AMMONIACAL COMPOUNDS OF LOBALT. 355 To prevent misunderstandings it may be as well to state that the radicals which I have here so freely used are not supposed to be in their compounds absolutely the same as in the free state The same remark applies with equal force to metallic bodies which on entering into combination give off a certain amount of heat and thus assume different properties. To say that metallic zinc is contained in its sulphate is an expression authorized by usage but is only strictly true by abstraction from most of the properties of the metal. The niaterial atom which under certain circumstances possesses the pro- perties which we describe by the word “zinc,” is no doubt contained in the sulphate but with different properties and in the chloride with properties different from either; so also of the compound radicals.It is to be hoped that we may soon be able to give an account of the nature of the processes by which these changes of properties are effected; but that task can only be entered upon when we have ob- tained exact determinations of the relative momentum of atoms in various compounds the proportion of which to their masses deter- mines their physical and chemical properties. On a Class of Ammoniacal Compounds of Cobalt. By Frederic Claudet.* When ammonia is added in excess to a solution of protochloride of cobalt mixed with four times its weight of chloride of ammonium the solution becomes of a dark brown colour without any appearance of a precipitate.In this state the solution rapidly absorbs oxyeen from the air; and on frequently agitating a bottle half-filled with it removing the stopper from time to time to renew the air the absorption is much facilitated and is complete in the space of three or four days the colour of the liquid changing at the same time frorn dark brown to an intense violet-red. If the air be replaced in this experiment by pure oxygen gas the oxidation is still more rapid and may be completed (if the quantity of solution be not too large) without requiring the removal of the stopper. By boiling this oxidized arnrnoniacal solution strongly acidified with hydrochloric acid a heavy crimson powder is deposited.A slight effervescence takes place at the same time due to the evolution of a certain quantity of oxygen and the liquid becomes Dearly colourless owing to the precipitation of the whole of the cobalt in the form of the new compound. The liquid when cold is drawn off from the red powder * Phil. Mag. [4] 11 253 MR. F. CLAUDET ON which is washed several times by decantation with distilled water thrown on a filter and allowed to dry in a warn1 chamber. The precipitated powder thus obtained is nearly pure. Before examination it is however necessary that it should be crystallized. The powder for this purpose is dissolved in boiling water to which a few drops of hydrochloric acid have been added; and on cooling the salt is deposited in tbe form of regular octohedrons small sparkling and of a ruby-red colour very much resembling small crystals of chrome- alum.This salt which is an intense cdouring matter is sparingly soluble in cold water 1 part requiring at GOO F. 244 parts of water ; it is soluble to a much larger extent in water at the boiling-point to which it imparts a very deep red colour; it is however slightly decomposed and altogether so on boiling the solution; but this may be prevented by keeping the solution slightly acid with hydro- chloric acid. Hydrochloric acid and saturated solutions of chloride of ammonium and sodium completely precipitate the new salt from its solution; alcohol acts in the same way. The salt is not decomposed by boiling hydrochloric acid.Sulphuric acid evolves hydrochloric acid a cor- responding sulphuric salt being formed ;the reaction however is not complete for at the end of the operation chlorine comes off from some decomposition. Nitric acid partially transforms the salt into the nitrate of the base. Potash and soda decompose the solution of the salt a hydrated peroxide of cobalt being thrown down and am- monia evolved in considerable quantity. Hydrate of baryta decomposes the salt in the same way with the aid of heat but not in the cold. Carbonate of potash or soda has no effect. Yellow prussiate of potash gives with a solution of the salt a dirty brown precipitate red prussiate none ;but on standing bright yellow needles crystallize from the solution.Sulphuretted hydrogen precipitates the whole of the cobalt as a bisulphide of that metal ammonia being liberated at the same time. The analysis of three different preparations of this sulphide gave- Found. Calculated. /--Ap- 7 Cobalt . . p-A-29.5 47-36 4i.9 11. 49.5 111. 48.2 Sulphur . . 32.0 52.04 51.1 50.5 51% 61.5 100-00 On boiling a solution of the new salt it is decomposed into ammonia which escapes and a superior hydrated oxide of cobalt containing a certain amount of a nitride of cobalt which is precipi- tated nothing but chloride of ammonium remaining in solution. A CLASS OF AMMONIACAL COMPOUNDS OF COBALT-357 The composition of the precipitated oxide of cobalt appears to be Co30++3H0. Dried in the air the salt contains no water of crystallization neither does it contain oxygen.When heated to low redness in a glass tube a large quantity of ammonia is disengaged a certain quantity of chloride of ammonium sublimed and a residue of com-mon protochloride of cobalt remains. In this reaction no moisture is produced which would necessarily be formed if any oxygen existed in the compound. The analysis of this salt was effected in the following manner. The chlorine was estimated from the chloride of silver obtained on boiling the solution with an excess of nitrate of silver and nitric acid. In the cold the precipitation by nitrate of silver is not complete. The cobalt was determined by reducing a certain quantity of the substance introduced into a tube with a bulb by pure hydrogen and heat.The nitrogen was estimated as ammonia by distilling the salt with caustic soda receiving the ammonia into hydrochloric acid and determining the weight of the double chloride of platinum and animonium. The ammonia was also obtained by heating the salt with soda-lime according to the method of Will and Varrentrapp. This last process however gave less accurate results a deficiency of about 1 per cent in the nitrogen being found. The hydrogen was determined by combustion of the salt with a mixture of oxide of copper and chromate of lead and copper turnings. The number of equivalents of chlorine cobalt nitrogen and hydrogen thus determined are 3C1 2C0 5N and l6H :-Found. Calculated. r-A-- 7 -rr- 11.111. 3C1=106*5 42.2 4.&22 42.38 42.25 2Co= 59.0 23.46 23-63 23.50 23-66 5N= 7'0.0 27.83 27.20 27.79 16H= 16.0 6.36 6.31 6.34 6.46 251.5 100*00 The salt containing a large quantity of chlorine it might be expected that the volatilization of minute quantities of chloride of copper or chloride of lead in the combustion would give an increase in the results for the hydrogen one equivalent of the latter making a difference only of 0.37 per cent. The results obtained however agree pretty well together ; and as they do not differ much from the calcu- lated numbers it is highly probable that sixteen is the true number of equivalents of hydrogen in the salt; and this view is further con- firmed by the manner in which the salt is decomposed by heat.A combustion-tube about two feet long was closed at one end and bent at right angles within about half an inch of the closed end so as to MR. F. CLAUDET ON form a kind of retort. A certain quantity of the salt was rubbed into a paste with a little water and rolled up into the size of a pea. When quite dry this was dropped into the tube and made to enter the small retort; mercury was then gently poured into the tube which was gradually filled and then inverted in a mercurial trough. The mercury descended about a quarter of an inch in the tube on account of a small quantity of air which remained in that portion containing the salt The retort part of the tube was now slowly heated by means of a spirit-lamp until the salt was entirely decomposed The gas produced occupied nearly the whole of the tube which was two feet in height.On allowing the tube to cool and intro- ducing a small quantity of hydrochloric acid the whole of the gas was absorbed with the exception of a column of about three-quarters of an inch in height showing that the space above the mercury was entirely composed of ammoniacal gas. Now the decomposition of this salt into no other gas than ammonia and no other solid products than chloride of ammonium and protochloride of cobalt is only com- patible with a certain number of atoms of hydrogen which is sixteen ; for-3C1,2Co 5N 16H =2CoCl+ NH,Cl+ 4NH,. Had there been one or two equivalents less of hydrogen one equi- valent of ammonia would have been broken up giving hydrogen and nitrogen not condensed by the hydrochloric acid.Assuming then the above number of atoms to be correct and applying Berzelius’s theory of the copulated compounds the formula of this salt may be written- 3(NH4C1) +2(NH,Co) ; that is a compound of 3 equivalents of chloride of ammonium with 2equivalents of an ammonia in which 1atom of hydrogen is replaced by cobalt. In fact the salt has the characters of such conjugate compounds. It has the properties of chloride of ammonium with regard to form and taste; while on the other hand the basic pro- perties of the 2 equivalents of ammonia have totally disappeared the salt being quite neutral to test-paper. This compound is analogous to the remarkable platinum-compounds discovered by Gros and Reiset but with this difference that it is a sesqui-conjugated corn-pound if it may be so called being composed of 3 equivalents of the salt united with 2 equivalents of the adjunct.Another way of irouping the ator& f this compound is the following proposed by Mr. Graham :-NII co, C1 NH, NH, { NH, NB Here NH Go represents an ammonium n which 2 equivalents of A CLASS OF AMMONIACAL COMPOUNDS OF COBALT. 359 hydrogen are replaced by 2 equivalents of cobalt; while NH NH represents an ammonium in which 1 cquivalent of hydrogen is replaced by ammonium itself as the hydrogen of ammonia is replaced by ethyl methyl &c. in Wurtz’s and Hofrnann’s bases. Or ClN{ H2 +2C1NiN3W H CO 4 The compound would then be viewed as a double salt composed of one equivalent of a chloride of cobalt-ammonium and 2 equivalents of a chloride of ammonium in which the fourth atom of hydrogen is replaced by ammonium.This peculiar compound has the property of forming double salts with bichloride of platinum and protochloride of mercury. Double salt with bichloride of ptatinum.-On adding a warm solution of the salt to bichloride of platinum in excess a silky cry- stalline buff-coloured precipitate falls down much less soluble than the salt itself; it may therefore be washed with water thrown on a filter and dried. 12 grains of this double salt were fused with carbonate of soda dissolved in hot water and filtered to separate the platinum and oxide of cobalt. The solution neutralized with nitric acid and preci- pitated with nitrate of silver gave 20.1 I grs.Ag C1=4*975 C1=41*6 per cent. The filtrate of platinum and oxide of cobalt after being ignited was treated with boiling hydrochloric acid which dissolved out the cobalt and left 4-05platinum =33.75 per cent. 18-59 grains of double salt reduced by hydrogen gave 8.06 mixed metals=43-35 per cent giving 9.60 per cent for the cobalt. The double salt is consequently composed of 1equivalent of the new compound and 2 equivalents of bichloride of platinum. Calculated. r-- Found. 5C1 =248*5 42.12 41.60 2Pt -256.2 33.43 33.75 2co= 59 10 9.60 5N- 70 16H = 16 the formula of which is- When this salt is decomposed by heat treated with nitro-hydro- chloric acid and the excess of acid driven off by heat the solution crystallizes in large orange-brown prismatic tables no mother-liquor remaining.This salt proves to be a double chloride of platinum and cobalt the 2 equivalents of bichloride of platinum combining MR. F. CLAUDET ON with 2 equivalents of protochloride of cobalt from the new con?-pound. Double salt with protochloride of mercury. -Prepared in the same way as the preceding double salt by adding a warm solution of the cobalt-salt t-oan excess of protochloride of mercury a bulky silky pre- cipitate is formed composed of small red needles. This may be collected on a filter slightly washed with cold water and recrystallized from ti warm solution the double salt being tolerably soluble in hot water.15 grains fused with carbonate of soda in the same way as the double platinum-salt gave 18-10grs. Ag C1==4.477 C1=29*84 per cent. 14.16 grs. reduced by hydrogen gave 0.10 cobalt=5*65 per cent. Calculated. F-A-Found. 9C1 =319.5 30.66 29.89 6Hg=600 aco-59 5.54 5.65 5N = 70 16H = 16 This double salt contains therefore for 1 equivalent of the cobalt compound 6 equivalents of protochloride of mercury. NH,Co 6Hg C1. { 2(NH NH,) + Recently prepared oxide of silver throws down the chlorine from the new ammoniacal compound a highly alkaline red solution remain- ing not having the slightest odour of ammonia. On standing for a few hours it decomposes ammonia is evolved and hydrated peroxide of cobalt precipitated. The compound in solution represents before changing the base of the present class of salts.It is an oxide of which the composition is the same as that of the chloride already described with the substitution of 3 equivalents of oxygen for 3 equivalents of chlorine :-a N H,Co Formula of new cobalt base . . 0 NH,NH,. { NH,NH The study of this and other allied compounds of cobalt which exist will no doubt greatly extend our views respecting the compound ammonias. The chlorineof the original chlorideinay also be eliminated by any silver-salt an analogous cobalt-salt containing the acid of the silver salt being formed and remaining in solution. In this way a sulphate . nitrate oxalate acetate and carbonate of the new base have been obtained. From the carbonate the aathor has prepared the bromide A CLASS OF AMIMONTACAL COMPOUNDS OF COBALT.361 andiodide which have the octohedral form of the chloride are just as sparingly soluble in water and of a still darker ruby colour. The bromide was found to contain 61.15 per cent of bromine the calcu- lated amount being 61.8 per cent. The insolubility of this amrnoniacal compound of cobalt in boiling hydrochloric acid may be advantageously turned to account in the preparation of chemically pure cobalt and also in the qualitative examination of substances containing small quantities of cobalt. The pulverized ore or its oxide to be purified is dissolved in nitro-hydro- chloric acid diluted with water and filtered in order to separate any gangue or insoluble residue.Chloride of ammonium is now added in large excess and the liquid saturated with ammonia; it is then poured into a glass bottle and oxidated in the way already described in the preparation of the new salts. During the oxidation a certain quantity of the new compound is deposited especially when the solutions are rather concentrated on account of its insolubility in a strong solution of chloride of ammonium. The solution still retains a certain quantity of cobalt-salt ; it is therefore boiled with a considerable excess of hydrochloric acid which causes the total precipitation of the new compound dissolving at the same time any oxide of iron or other oxides thrown down by the ammonia. -%.'hen cold the clear liquid is decanted off and the deposit well washed with acidulated water and then dried.By heating this compound to low redness it is decomposed leaving for residue protochloride of cobalt slightly decomposed but absolutely free from any other metal. This may be reduced by hydrogen gas giving pure metallic cobalt. By these means the author has been able to prepare perfectly pure cobalt directly from the grey cobalt-ore of Tunaberg which is an arsenio-sulphide of cobalt and also to detect srnall quantities of cobalt in different samples of oxide of nickel. The preceding results embody the most definite conclusions of an investigation of the arnmoniacal salts of cobalt which Mr. F. Claudet has had in hand for the last two or three years. M. Fr6my has also lately announced that he is occupied with an extended inquiry into the same class of compounds respecting which he has published some important general results.* Dr.A. Genthf appears also to have formed several of the salts of the new base above described but his analytical results differ entirely from those given in the present paper. * Compt. Rend. April 7 1851 and May 26 1851. f Chem. Gaz. 1851 286. M. BOUIS ON THE CAPRYLIC ALCOHOL. On the Composition of Ricinolamide and the Prodnction of Caprylic Alcohol. By J. Bouis.* When castor-oil is placed in contact with ainnioiiiacal alcohol or simply with aqueous ammonia a solid compound is formed which is the amide of ricinolic acid or Ricinolamide C, H, NO,. It is white ; crystallises in manimellated masses ; fuses at 66' C.;is in- soluble in water but soluble in alcohol and ether ; and burns with a very smoky flame. It is not attacked by potash in the cold but when boiled with a strong solution of potash it gives off ammonia and is converted into ricinolate of potash. The ricinolic acid obtained by this process of saponification has the composition c36 H, 06 ;other products however are formed at the same time. The action does not take place till the potash parts with its water and begins to fuse. A volatile liquid is then given off; and if the mass be afterwards dissolved in water and the solution treated with hydrochloric acid a mixture of two oily acids one liquid and the other solid rises to the surface The liquid portion is ricinolic acid and the solid portion sebacic acid C, H, 0,.The latter is not contained in the ricinolainide but is produced together with the volatile oil above-mentioned by the decomposition of the ricinolic acid. The sebacic acid and the volatile liquid may however be much more conveniently obtained by simply heating castor-oil with a very strong solution of potash (or better with the solid hydrate). A volatile oil having an agreeable aromatic odour is theD given off in quantity amounting to one-fifth of the castor-oil employed and sebate of potash remains in the retort. The volatile oil is transparent ;stains paper like essential oils ; is insoluble in water but soluble in alcohol ether and acetic acid; and burns with a very beautiful white flame. Its density is 0.823 at 19O and boiling-point 180' C.Its composition is expressed by the formula C16 Hl8 0,. The theoretical density of its vapour is 4.49;experiment gives 4.50 = 4 volumes. Sulphuric acid dissolves it and the mixture forms crystallisable salts with lime and baryta. When heated with sulphuric acid it is transformed into a hydrocarbon c]6H,6 which is very fluid lighter than water burns with a very brilliant flame boils without decom- position at 125O and forms a vapour whose density is by calculation 3.86 by experiment 3.90=4 volumes. Fused chloride of zinc con- * Compt Rend. XXXIIJ 141. MR. HOW ON COMENIC ACID. verts the volatile oil into a mixture of several isomeric hydrocarbons the most abundant and volatile of which is identical with that formed by the action of sulphuric acid.Chloride of calcium dissolves in the volatile oil and the solution yields very beautiful transparent crystals which are decomposed by heat and by the action of water. The com-pound is less soluble at high than at low temperatures. The action of nitric acid varies with its strength ;by long continued digestion with dilute nitric acid the oil is converted into pimelic lipic succinic and butyric acids.-Acetic and hydrochloric acid convert it into ethers having very aromatic fruity odours.-Quick lime at a high temperature transforms the oil into free hydrogen and gaseous hy drocarbons.-Potash-lime or soda-lime has no action on the oil at 250° C.; but at higher temperatures very pure hydrogen is evolved and a volatile acid formed which remains combined with the potash.All these facts show that the volatile oil belongs to the class of alcohols. It is in fact caprylic alcohol and takes its place in the series between amylic and ethalic alcohol.-Its formation by the action of potash on castor-oil is represented by the following equa- tion U w+ Ricinolic acid. Sebate of Caprylic potash. alcohol. On Certain Salt8 and Products of Decompositfon of Comenic Acid. By Heliry HOW.* Thals research was undertaken with the view of extending our knowledge of the polybasic organic acids the study of which as the author observes has scarcely kept pace with that of other classes of organic bodies. Comenic acid was discovered by Robiquet,? who observed that meconie acid undergoes a change of properties when boiled with water carbonic acid being evolved and a product obtained to which he gave the name of parameconic acid,indicative of isomerism with the original substance.Liebig,$ however pointed out that there was also difference in composition and proposed the provisional name metameconic acid for the new substance whose compositioii he *Trans. Roy. SOC. of Edinb. XS,225. t Ann. Ch. Phys. [2] LI 214. $Ihd. LIV 26. VOL. I\'.-NO. XVI. cc MB. HOW ON CERTAIN SALTS AND 364 represented by the formula C, H Ole derived from the analysis of the acid itself and of a silver-salt. In a subsequent paper* he showed its bibasic nature and entered fully into the relations which this acid now called comenic acid bears to meconic acid and to para- meconic acid the product of dry distillation common to both the former bodies.The sub-ject has been further discussed by Dr. St en-house in a paper published in the first volume of the “Memoirs and Proceedings of the Chemical Society.” The comenic acid used in the anthor’s experiments was prepared by boiling crude meconate of lime (or still better the acid-salt obtained by once treating this substance with boiling water and hydrochloric acid) with a quantity of tolerably strong hydrochloric acid sufhcient to dissolve it whereby the acid was obtained in hard crystalline grains of a very dark colour. This crude product was purified by boiling it in water with gradual addition of caustic am- monia sufficient to dissolve it-care being taken not to add an excess- and immediately filtering the liquid which on cooling deposited bicomenate of ammonia in hard yellow crystals if left at rest but in soft silky prisms if agitated; in the latter state the salt is difficult to wash.By two or three crystallizations from boiling water it is obtained in fine radiated four-sided prisins of dazzling whiteness ; and on treating the solution of this purified salt with strong hydro- chloric acid comenic acid is precipitated in the form of a white heavy crystalline powder which adheres to the sides of the vessel. A satu-rated solution of this powder in boiling water in which it is not very soluble deposits the acid in grains and crusts almost colourless; but as the soliition cools groups of short prismatic or almost leaf- like crystals appear always possessing a characteristic yellowish-red tinge.SALTS OF COMENIC ACID. Bicomencrte of Ammonia-This salt was analyzed by Dr. Sten- house who prepared it by dissolving the acid in a slight excess of ammonia and evaporating in vucuo over sulphuric acid. He found it to contain 2 equivs. of water of crystallization which were given off at 212O making the formula of the hydrated salt NH 0.HO . C, H 0,+2 Aq The salt obtained by the preceding process agrees with this formula it is in the form of square prismatic crystals white and of great brilliancy very soluble in boiling water sliglitly soluble in alco- hol. It has a strongly acid reaction and is deposited even from a solution of the acid in excess of hot caustic ammonia if the boiling has not been long continued.A salt containing an additional atom * Ann. Ch. Pharm. XXVI. PRODUCTS OF DECOMPOSITION OF COBiENIC ACID. 365 of water is obtained by adding strong alcohol to a cold saturated solution of comenic acid in amnionia ; it falls in groups of radiated prisms. Bicomenate of ammonia in the dry state sustains a temperature of 350' F. without decomposition or loss of weight ;but nhen heated to 390' in a closed tube it blackens and fuses and undergoes a change which will be described further on. Bicomenate of Potash-Comenic acid dissolves readily in a slight excess of potash and the liquid on cooling deposits a salt \\7hich when washed with cold water and subsequently recrystallized froin the same menstruum at a boiling heat assumes the form of short square prismatic needles.They are anhydrous and have a strongly acid reaction. Their analysis gave results agreeing with the formula KO . €10. C, €I 0,. Bicoinenate of Soda.-When comenic acid is dissolved in a tole- rably strong and boiling solution of caustic soda the liquid on cooling deposits two forms of crystals one in nianimellated masses the other in transparent prisms half an inch long. On washing the mixture with a little cold water and redissolving in boiling water no deposit is obtained even after the lapse of some hours; but on evaporating the liquid to two-thirds of its bulk groups of mammillary crystals appear which when magnified are found to consist of four-sided elongated prisms.It appears then that bicomenate of soda is much more soluble than the corresponding potash and ammonia salts and cannot be advantageously employed in the preparation of comenic acid. It has an acid reaction and is anhydrous. The proportion of soda corresponds to the formula NaO . €10. C, H 0,. Neutral salts of coinenic acid with the fixed alkalies and with am-monia do not appear to exist in the dry state. With the alkalinc earths however the case is different. Bicomelzate of Lime.-When finely powdered comenic acid is mixed with cold water and an excess of carbonate of lime; the latter is partially decomposed with effervescence and the liquid when boiled and filtered deposits a few rhombic crystals doubtless consisting of the bicornenate.This salt however is much more conveniently obtained by adding a cold saturated aqueous solution of bicomenate of ammonia to a solution of chloride of calcium. Small brilliant crystals are then obtaincd consisting of perfcctly defined transparent rhombs; they dissolve readily in boiling water and the solution on cooling yields crystals of a larger size than those first obtained. The crystals contain 7 eqnivs. of water of crystallization which are not easily driven off at 212' but are completely expelled at 250'. The formula of the salt dried at that tcniperature is Ca 0 . f-I0 . CL 11 0,. c c 2 MR. HOW ON CERTAIN SALTS AND Neutral Comenate of Lime.-Obtained in the form of crystalline grains when a solution of bicomenate of ammonia mixed with excess of ammonia is poured into a solution of chloride of calcium.Accord-ing to the state of dilution of the liquids employed salts are obtained containing different quantities of water of crystallization and differing in appearance accordingly. In all cases however the salts when dried at 250' give results corresponding to the formula 2 Ca 0 . C, H 0,+2HO 2 equivs. of water being retained at that temperature. When the solutions used are tolerably dilute groups of minute prisms are ob- tained which give off 5 equivs. of water in drying; helice their for- mula is 2CaO. C, H20,+2HO+5Aq. From very dilute solutions small well-defined brilliant crystals are obtained which give off 11 equivs.of water in drying 2CaO. C,z H 0,+2 HO+ll Aq. All these neutral salts are converted into basic compounds by simple ebullition in water. Baryta-sah-Carbonate of baryta is partially decomposed by comenic acid in the cold and completely so when heated with an excess of water the acid comenate of baryta being produced. But when the acid is boiled in water with excess of carbonate of baryta effervescence ensues but the comenic acid remains undissolved being in combina- tion with the earth in the form of a basic salt. By double decomposi- tion both the neutral and acid salts are readily obtained. Bicomennte of Baryta.-A cold saturated aqueous solution of bicomenate of ammonia gives with chloride of barium an immediate precipitate having a crystalline character ;from more dilute solutions the salt is more slowly deposited in well-defined transparent rhombs.It is readily soluble in boiling water and has an acid reaction. It gives off its water of crystallization at 212O but very slowly. The dried salt fuses on ignition and gives by analysis results agreeing with the formula BaO . HO . C, H 0,. In the crystals. 2 equivs. of this substance are combined with 13 equivs. of water. Neutral Cornenate of Baryta.-Obtained in a similar manner to the lime-salt. Strong solutions yield minute radiated crystals ; but in dilute solutions the crystals are formed gradually and ultimately fill the whole of the liquid presenting under those circumstances a very beautiful appearance being arranged in separate groups whose silky needles radiate regularly from a centre.Under the microscope these needles present the appearance of square prismatic crystals. The salt is insoluble in boiling water and does not give off its water PRODUCTS OF DECOMPOSITION OF COMENIC ACID. 367 of crystallization at 21.2'. When dried at 250° it is almost pyro-phoric blowing up oltl ignition in a light fiery cloud. Its formula when dried at 25O0 is 2Ba0 . C, H O,+ZHO. The crystals contain 8 equivs. of water in addition. The crystallized salt when boiled in water is converted into a basic compound which gives off no water at 250'. Mugnesia S&.-The acid and neutral salts are obtained by double decomposition similarly to the lime and baryta salts.The acid comenate of magnesia is much more soluble than the corres- ponding salts of lime and baryta; when obtained from very dilute solutions by spontaneous or very slow artificial evaporation it forms very large crystals which when they possess the yellow coloiir SO apt to adhere to salts of comenic acid very much resemble crystals of ferrocyanide of' potassium. They dissolve readily in hot water forming a strongly acid solution. The salt when dried at 240' retains 2 equivs. of water; its composition when thus dried being MgO . NO . C,,H,O,+ZHO. Neutral Cornenate of Magnesia forms hard crystalline grains made up of groups of short prismatic needles. They are insoluble in boiling water and give off their water of crystallization at 212' but only after long exposure.The formula of the salt thus dried is- 2 MgO . C,,H,O,i-3 HO. and that of the crystals 2 MgO C,,H,O,+ 3 HO +8 Ay. The attempt to forin a salt containing 2 HO corresponding to the neutral comenates of lime and baryta dried at 240' was not successful. The comenates of strontia somewhat resemble those of baryta in appearance but are more soluble. Comenic acid does not form an acid salt with oxide of copper the salt containing 2 equivalents of base being obtained both by the addition of comenic acid itself and of acid comenate of ammonia to a solution of sulphate of copper. PRODUCTS OF DECOMPOSITION OF COMENIC ACID. By Oxidation.-Nitric acid converts comenic acid into carbonic oxalic and hydrocyanic acids.This action is produced even by very dilute nitric acid and is very rapid and violent when tolerably strong acid is employed. When comenic acid is boiled with solution of persulphate of iron a large quantity of carbonic acid is given off and a liquid formed con- taining much protoxide of iron and osalic acid. MR. HOW ON CERTAIN SALTS AND Comenic acid does not appear to be affected by sulphurous acid or sulphuretted hydrogen. Action of Chloriiie.-C~~lo?.ocomenic Acid.-When chlorine gas is passed thrmgh water holding .powdered comenic acid in suspension a portion of the acid is dissolved and the clear liquid after soine time deposits the new acid in colourless prismatic crystals. The acid is however more conveniently obtained by passing chlorine through a solution of the ammonia-salt.If an alkaline animoniacal solution of cornenie acid be exposed to the action of chlorine the first result is a precipitation of the acid comenate of ammonia; but if a cold saturated solution of the latter salt be employed and tlic gas passed through it for a long time the whole of the colour disappears without the formation of an immediate precipitate. After the lapse of soine hours long colonrless needles are deposited the quantity of which is increased by the addition of hydrochloric acid. The mother-liquor on gentle evaporation, gradually acquires a brownish tint which passes ultimately into a very dark brown and the liquid then deposits a further quantity of the new acid in prismatic crystals separate and in groups of a brown nearly black lustrous appearance.The second rnother- liquor contains oxalic acid in addition to the colouring matter The colourlcss crystals at first obtained were washed with cold water and recrystallized from boiling water in which they are readily soluble ; they acquired in this process a slight shade of yellow and presented themselves in the form of shoit thick square prisms. When deprived of their water of crystallization by a heat of 212O,they gave on analysis results corresponding with the formula Hence the new substance is an acid obtained by the substitution of an equivalent of hydrogen in coinenic acid by an equivalent of chlorine according to the following equation :-2HO. C,,H,O + 2C1= HO . Ci { tl} o,+ HCl.The crystals contain 3 equivs. of water of crystallization. Chlorocornenic acid is readily soluble in hot water less so in cold water; but in both cases its solubility is much greater than that of comenic acid. It imparts to persalts of iron the same deep colour as meconic and comenic acids. When a piece of granulated zinc is placed in its aqueous solution hydrogen is slowly evolved and both zinc and hydrochloric acid are found in the liquid. Nitric acid rapidly decomposes it with formation of hydrochloric h ydrocyanic carbonic aid oxalic acids. When submitted to destructive distilla- tion it fuses and blackens gives off hydrochloric acid in large PRODUCTS OF DECOMPOSITION OF COMENIC ACID. 369 quantity and towards the end of the process a small quantity of a crystalline sublimate appears probably consisting of pyromeconic acid.Chlorocomenic acid is bibasic and forms two series of salts analogous to those of comenic acid but generally speaking possessed of greater solubility. It does not appear to form neutral salts with the alkalies. The acid salts of potash soda and ammonia crystallize readily. A solution of the last-mentioned salt gives with the chlorides of calcium and barium radiated groups of needles which appear more or less quickly according to the state of concentration of the solutions; with sulphate of magnesia a few crystals after some time; with sulphate of copper a crystalline salt which separates rapidly from the liquid. The neutral salts of these bases appear to be generally insoluble amorphous substances .The acid silver-salt 2(Ag0 .HO .C,,HClO,) + 3 Aq is obtained in feathery crystals by treating a warm aqueous solution of the acid with nitrate of silver. The neutral silver-salt 2 Ago C,,HClO is a yellow flocky amorphous substance obtained by adding a solution of the acid in a slight excess of ammonia to nitrate of silver. It is insoluble in boiling water and acquires in the process of drying the consistence and adhesiveness of clay which it also closely resembles in appearance. Act.ion of 13romine.-Bromocomenic Acid.-The action of bromine on comenic acid is analogous to that of chlorine. Comenic dissolves in bromine yielding a colourless liquid if the bromine is not in great excess. In the course of a few hours the new acid is deposited in fine square prismatic crystals often of considerable length and presenting a very beautiful appearance from their high refractive power.The acid may also be obtained by the addition of bromine-water to solution of acid comenate of ammonia ;but this process is not so con-venient as the former. Bromomeconic acid when dried at 212’ is composed according to the formula and the crystals contain 3 additional equivalents of water. This acid closely resembles chloromeconic acid in its general properties ;it is however rather less soluble in hot water and in alcohol and is depo- sited from the alcoholic solution in fine rhombic crystals. It is decomposed by zinc and when treated with nitric acid gives off hydrobromic hydrocyanic carbonic and oxalic acids.The acid ammonia-salt crystallizes in fine long needles; the acid salts of potash and soda also crystallize. No neutral salts of the alkalies could be formed. The acid salts of the alkaline earths are very soluble ;the neutral salts insoluble and amorphous. The acid silver- MR. HOW ON CERTAIN SALTS AND salt is obtained in the form of a flocculent precipitate by adding an aqueous solution of hromocomenic acid to an aqueous solution of nitrate of silver. It is soluble in boiling water and is deposited from the solution in brilliant short prismatic crystals. The neutral silver-salt is obtained as a yellow amorphous precipitate on adding a solution of the acid in a slight excess of ammonia to nitrate of silver; when dried it presented the same clayey character as the chloro- comenate.Iodine does not appear to decompose comenic acid. Comenovinic Acid.-When comenic acid in the state of fine pow- der is suspended in absolute alcohol in which it is insoluble per se and a stream of dry hydrochloric acid passed through the liquid the whole or the greater part of the acid is slowly taken up. The clear solution when evaporated to dryness at a temperature somewhat below 212O leaves a crystalline residue which when freed from adhering hydrochloric acid by gentle heating and recrystallized from water below the boiling point yields wrell-defined square prismatic needles of considerable size. These crystals dried in uacuo and analysed gave results corresponding to the formula C16H Ole or HO .C H 0 .C, H 0,. The new substance is therefore Cornelzovinic acid and analogous in composition to sulphovinic tartrovinic acid &c. The crystals are anhydrous. Cornenovinic acid is readily soluble in hot water and may be boiled for a short time without decomposition ; but if long kept at this temperature it is decomposed and comenic acid produced. It is extremely soluble in alcohol. In the dry state it begins to volatilize at 212'. At 275O it fuses into a transparent brownish liquid which on cooling becomes a crystalline striated mass. When kept at a temperature near its melting point it sublimes unaltered in composi- tion in brilliant long flattened prisms of great beauty. It is strongly acid to test-paper.Its aqueous solution readily coagulates white of egg and imparts a deep red colour to persalts of iron. Comenovinic acid rapidly decomposes in contact with fixed bases ; hence the author has not been able to obtain any of its salts in the dry state. The ammonia-salt is obtained in silky yellow tufts by passing dry ammoniacal gas into a solution of the acid in absolute alcohol ;it preserves its silky appearance when dried but soon begins to give off ammonia in a dry atmosphere. The comenovinates of the alkalies and alkaline earths are very soluble. The silver-salt is gelatinous and decomposes rapidly even in the dark. DECOMPOSITION OF COMENATE OF AMMONIA. Comenamic Acid.-When a solution of comenate of ammonia containing an excess of alkali is boiled it soon becomes coloured and after some time a black-red fluid is obtained.If the boiling be con- PRODUCTS OF DECOMPOSITION OF COXENIC ACID. 371 tinued till the whole or the greater part of the ammonia is expelled and the liquid then allowed to cool a grey sediment falls down which when thrown on a filter is found to have a most peculiar clayey tcnacious character. It is the ammonia-salt of comenamic acid much contaminated by adhering colouring matter. It dissolves though sparingly in boiling water and hydrochloric acid added in just sufficient quantity to decompose it precipitates the acid in very dark bronze-coloured scales which separate completely as the liquid cools. The crystals may be readily decolorized by two or three crystallizations from boiling water or better by means of animal charcoal free from iron.The pure crystals dried at 212O gave results corresponding to the formula C, H 0 N ;whence it appears that the new substance is ail acid amide analogous to oxamic acid and its constitution is ex- pressed by the formula of acid comenate of ammonia minus 2 atoms of water HO . NH .C,,H,O,. The crystals contain 4 atoms of water of crystallization. Comenamic acid is likewise formed when bicomenate of ammonia is heated to 390' Fahr. in a sealed tube. A black coaly mass is then obtained partly soluble in boiling water; and the filtered liquid treated with hydrochloric acid yields comenamic acid in the form of a white scaly precipitate. The acid as obtained by the first process forms brilliant scales very slightly soluble in cold water; they efloresce and lose their lustre in a dry atmosphere.It is soluble in boiling spirit but very slightly in absolute alcohol. It has a strong acid reaction dissolves readily in excess of alkali and with extreme facility in the strong mineral acids. From a solution in any of these acids ammonia added in quantity not quite sufficient to neutralize the whole of the solvent throws down a granular precipitate of the ammonia-salt. The aqueous solution of comenamic acid imparts to persalts of iron a magnificent and deep pure purple colour which is destroyed by a few drops of mineral acid but reappears on dilution with water. Comenamic acid is decomposed by boiling with caustic potash with evolution of ammonia and production of cornenic acid.With a certain proportion of potash soda or ammonia comenamic acid forms crystallizable salts which have an acid reaction. The formula of the ammonia-salt is NH 0.C, H NO,. Comenamic acid dissolves the earthy carbonates with effervescence. When the acid is in excess a crystalline salt with an acid reaction is obtained; but with an excem of carbonate nearly all the acid remains undissolved in the form of a basic compound. A solution of the crystalline ammonia-salt gives with nitrate of 372 T. H. ROWNEY ON A NEW SOURCE FOR OBTAINING silver a white gelatinous precipitate partially decomposed by boiling water. The same solution made alkaline gives with nitrate of silver a yellow flocky precipitate which almost instantly begins to darken in colour and ultimately becomes black and amorphous.The same solutions give with acetate of lead heavy insoluble precipitates ; the acid solution gives with sulphate of copper a grey precipitate. By adding a solution of the ammoilia-salt to chloride of ba-rium a crystalline salt was obtained having the composition BaO .C12H NO,; and supposing it to be the neutral salt of a monobasic acid it may be expressed by the formula BaO .C, 11 NO +2HO. By treating an alkaline solution of the ammonia-salt with chloride of barium a heavy white powder is obtained insoluble in boiling water and composed of 2BaO. C, H NO,. To assimilate this salt to the last it must be regarded as a basic compound in which one of the equivalents of water retained at 212' is replaced by baryta ;thus BaO .C, H NO +BaO .HO.As precipitated from water it retains an additional equivalent of water. The lime-salts are very similar in appearance to the baryta-salts and with every base this acid seems to form two salts which is a curious fact since reasoning from analogy a substance originating as it does should be monobasic in its character. In conclusion the author mentions that he has noticed in the behaviour of comenaniic acid under certain circumstances phenomena which are likely to repay further investigation. On a New Source for Obtaining Cayric Acia and Remarks on so818 of its Salts. By T.H. ROwneyZ Capric acid has been obtained from various 8ources.Chevreul and Lerch discovered it in the butter of the cow and goat; Red- tenbacher among the volatile oily acids which he obtained by acting upon oleic acid with nitric acid; Gerhardt and Cahours produced it by the action of nitric acid upon oil of rue; and Gorgey found it in cocoa-nut oil. From all these sources however it has been obtained in small quantity only and always mixed with other acids of the same series. The new source from which Mr. Rowney has obtained this acid is the fusel-oil or grain-oil of the Scotch distilleries. This oil chiefly * Trans. Roy. Soc. Edinb. XX,219. CAPRIC ACID AND REMARKS ON SOME OF ITS SALTS. 373 consists of water alcohol and the hydrated oxide of amyl in various proportions but sometimes contains small quantities of other consti- tuents thus oenanthic ether was found in it by Mulder and rnargaric acid by Kolbe.The oil examined by Mr. Rowney was foimd to contain capric acid probably in combination with oxide of amyl. On subjecting the grain-oil to fractional distillation the first portions which passed over consisted chiefly of water and alcohol with a little hydrated oxide of amyl; the second portion was com- posed of the latter substance nearly pure ;and a dark-coloured residue was left which had a disagreeable odour was insoluble in water and carbonate of potash but was rendered soluble in water by boiling with a strong solution of caustic potash amylic alcohol being at the same time given off. Digestion for two or three days on a sand-bath with strong solution of potas21 likewise renders the oil soluble in water.On adding hydrochloric or sulpburic acid to the cold alkaline solution a dark oily niass consisting of impure capric acid rises to the surface. To purify this product it was dissolved in dilute ainmonia after filtering and washing with cold water; the solution mixed with chloride af barium ; the resulting precipitate filtered and washed with cold water ; afterwards dissolved by boiling water; and the solution filtered whilst hot and then left to crys- tallise. The baryta-salt thus obtained was purified by two or three crystallisations then decomposed by carbonate of soda and dilute sulphuric acid added to the filtrate to separate the capric acid.The product was solid and nearly colourless; but to obtain it perfectly pure it was dissolved in alcohol and the solution mixed with a large quantity of water whereupon it became turbid and after some hours deposited capric acid in the crystalline state. By repeating this process the acid was obtained quite pure and colourless. The mother-liquors from the baryta-salt yielded a further portion of capric acid together with an oily acid the quantity of which was however too small to allow of its constitutioii being determined. Capric acid thus obtained is a solid white crystalline compound which has a faint odour and fuses readily between the fingers. It is very soluble in ether and alcohol and does not crystallise from these solutions. It is insoluble in cold water but dissolves sparingly in boiling water and crystallises from the solution on cooling in the forin of scales.It is also dissolved without decomposition by strong boiling nitric acid and is precipitated from the solution by water. From the alcoholic solution it is obtained by the addition of water in a mass of needle-shaped crystals. It is lighter than water. The crystallised acid begins to fuse at 81O F. but the temperature rises to 116O before the fusion is complete. The fused acid is slightly coloured has a faint odour and becomes crystalline on cooling. The crystallised acid dried in vaczto gave by analysis results agreeing with the formula C, H, 0,. ON CAPRIC ACID. Caprate of silver C, €Ilg Ag O, is obtained by adding nitrate of silver to an ammoniacal solution of capric acid.It is insoluble in cold water sparingly soluble in boiling water and is deposited from the solution in needle-shaped crystals on cooling. It is more soluble in boiling alcohol ; but the solution becomes dark-coloured and the crystals obtained frorn it are also dark-coloured. It is very soluble in ammonia and if the amrnoniacal solution be kept in a warm place so as to drive off the ammonia a crystalline salt is obtained. Caprate of silver blackens rapidly if exposed to bright daylight while moist but after drying the light no longer affects it. Caprate of baryta C, H, Ba O, is obtained by adding chloride of barium to an ammoniacal solution of capric acid. It is soluble both in water and in alcohol at the boiling-points and crystallises out on cooling in needle-shaped crystals.This salt as well as the salts of the other alkaline earths and the silver-salt are insoluble in water after having been dried because they float on the surface of the water and repel it; but if first moistened with alcohol they may be again rendered soluble in boiling water. They are also very difficult to pulverise. The caprates of lime and magnesia are similar to the baryta-salt but more soluble in alcohol and boiling water. The quantity of base in the magnesia-salt agrees with the formula C, €Il9Mg 0,; the lime-salt was not analysed. The other salts of capric acid do not crystallise readily. The copper-salt is insoluble in water and alcohol but soluble in ammonia.The lead-salt is insoluble in water and very sparingly soluble in boiling alcohol which deposits it in rounded grains on cooling. The soda-salt is exceedingly soluble both in water and alcohol and does not crystallise from these solutions; when evaporated to dryness it forms a hairy mass partially crystalline on the surface. None of these salts could be obtained in a state of purity and their analyses gave an excess of base; but the copper and soda-salts appear to be neutral. Capric ether was obtained by dissolving the capric acid in absolute alcohol passing dry hydrochloric acid gas into the solution to satura- tion and then adding water which caused the capric ether to rise to the surface in the form of an oily liquid. After washing with cold water and drying with chloride of calcium it had a density of 0.862.It is insoluble in cold water but readily soluble in alcohol and ether. The quantity obtained was too small for analysis. Cupramide.-'l'he capric ether was converted into this compound by solution in alcohol and long-continued digestion in a stoppered bottle with strong ammonia. After a few days the solution became turbid and subsequently crystals made their appearance. The digestion was coiitinued till the whole of the ether had disappeared after which the solution was separated from the crystals by filtration; the filtrate evaporated to dryness over the water-bath ;the residue ON THE SUPPLY OF WATER TO THE NETROPOLIS. 375 dissolved in alcohol ;and the solution mixed with water which caused the capramide to crystallise; the whole was then dissolved in warm dilute alcohol and allowed to crystallise.Cayramide thus obtained is quite colourless and crystallises in brilliant scales which when dry have a bright silvery lustre. It fuses below 212*,is insoluble in water and ammonia very soluble in cold alcohol and also in dilute alcohol when warmed with it. Analysis gave results in accordance with the formula C, H, 0 N. Chemical Report on the Supply of Water to the metropolis. Letter from the Rzght Hon. Sir George Grey Bart. Principal Secretary of State for the Honie Department. Whitehall 23rd January 1851. GENTLEMEN I herewith transmit to you a copy of the Report of the General Board of Health on the Supply of Water to the Metropolis together with the ,4ppendices containing the Evidence on which the Report is founded and some otber Papers printed by the Board in connection with this subject.T also transmit a copy of the Evidence taken before the Select Committee of the House of Commons during the Session of 1850 on the River Lea Trust Hill. I have to request that after a consideration of these Documents you will report to me for the information of the Government your opinion upon the following Questions namely What is the chemical quality of the various waters which are now supplied to the metropolis ? T;TThat is the chemical quality of the water derived from the sources whence the Board of Health propose to supply the metro-polis ? What is the chemical qua?itv of the water proposed to be sup- plied from Watford ? Whether if the quality of the water now supplied be objection- able any remedy can be applied by filtrstion OF otherwise without abandoning the present sources of supply ? Whether if soft water were to be obtained in sufficient quan- tity for the supply of the metropolis any comparative incoiivecience w-ould arise from the use of such water under the present system of CHEMICAL REPORT ON THE distribution and if so whether available means may be found of obviating it ? What are the properties to be preferred in the water selected for the supply of the metropolis ? As much inf~rmation upon this subject has been collected in the Papers now transmitted to ycu I hope that you may be enabled to form your opinion without the delay which would be incurred by the taking of additional evidence but it will be competent to YOU if you think it necessary to ask for further explanations from any of the parties who have already given evidence upon the subject or to call for information from other parties.1 have the honour to be Gentlemen Your obedient servant G. GREY. THOMAS GRAHAM ESQ. F.R.S. W. A. MILLER M.D. F.R.S, A. We HOFMANN Ph.D. F.R. . REPORT. SIR We have the honour to report to yoa our opinions on the Ques-tions respecting the Metropolitan Water Supply which are proposed for our consideration in your letter addressed to us of the 23rd of January last as follows 1.-OF THE CHEMICAL QUALITY OF THE PRESENT SUPPLY.It appeared unnecessary to include in this inquiry the water drawn from the shallow wells sunk into the superficial strata within the confines of the metrapolis as the supply from these w~Ilais insignificant and in the course of still farther diminution in quan- tity and o€ten of deterioration in quality from obvious causes. The deep well-water also obtained by penetrating through the great clay beds to the chalk below although of imporeatice to the propriet~s~ of breweries and to other manufacturers who have incurred the expense of sinking wells on their prerniavs is of comparatively little general interest as this source of supply is not expansive and appears to be already fully appropriated. It is to the cheiraical quality of the water furnished to the metropolis by the several water c~mp~.~i~ that we shall therefore confine our observations under the prescmt head.SUPPLY OF WATER TO THE METROPOLIS. The existing Metropolitan Water Companies with their estimated delivery per day are as follows :* Gallons per day. Grand Junction Company . 3,541,717 a Water derived from West Middlesex . . . * 3,334,054 the Thames c Chelsea . . . . * 3,940,730 19,907,480 gallons. Southwark and Vauxhall . . 6,013,716 Lambeth . . . . 3,077,260 Water derived from New River . . . . 15,435,617 other sources than the East London . . 9,036,049 (I Thames 25,973,445 Kent . . . . . 1,079,311 gallons. Hanipstead . . . . 427,468 I 45,885,925 It thus appears that of a daily supply of nearly 46 million gallons 20 million gallons are taken from the Thames and 26 million gallons are obtained from other sources These latter souxes are for the New River Company Chadwell Spring in the chalk strata near Ware the river Lea above Ware Spital- brook and other small springs taken into the River ;the water-shed of the North-hall district and four deep wells sunk into the chalk in Middlesex and Hertfordshire (two being in Great Amwell).The supply of the New River Company from the Lea is at present limited to 1340 cubic feet per minute. But the River Lea Navigation Trustees have applied to Parliament for powers to construct reser-voirs on the upper part of the Lea and upon its tributaries the Rib and Ash in order to enable the trustees to increase the New River supply Of the East London Company the supply is taken from the Lea at a point six miles from its mouth at Bow Creek and two miles beyond reach of the tidal waters of the Thames which ascend some distance up the River Lea.The Kent Company which supplies Deptford Greenwich and Woolwich takes its supply from the Ravensbonrne below Lewisham. Harnpstead ; springs at Hampstead Caen Wood two artesian wells arid (temporarily} the New River Of the Tharnes companies the Lambeth at present takes its water at bambeth the lowest point at which water is drawn from the river. But this company will very shortly be supplied from their new works at Thames Ditton near Kingston which is a higher source than any other Thames company yossp -bSes.7 The Chelsea and the Southwark-Vauxhall Companies from near the Red House Battersea above Vauxhall Bridge. The West Middlesex from near Barnes Terrace in thc parish of * Calculated from the last returns made by the Water Compaaies to the General Board of Health and communicated to this Commission with much other valuable in- formation by the Board. CHEMICAL REPORT ON THE Barnes; and the Grand Junction a little way higher up 360 yards above Kew Bridge. Of these points on the river from which water is drawn it may be said that those of the Lambeth Chelsea and Southwark-Vauxhall works are within reach of the return tidal flow of the Thames from London Bridge while the sources of the Grand Junction and West Middle- sex appear to be above the influence of the returning tide from any point so low as to receive a share of the London drainage.It should be added however that in a favourable state of the tide a very sensible improvement in the appearance of the Thanies is observed above Vauxhall Bridge and that the river there begins to assume the character which it maintains up to Richmond. The whole Thames Water Companies draw from this improved section of the river except the Lambeth Company which will soon be otherwise supplied. Specimens of the water of all the Companies mere taken for analysis always from a main and generally at the nearest acces-sible point to the works of the Company or to a distributing reser- voir. They were all drawn on the 29th 30th and 31st of January last after moderately rainy weather with the river full but not flooded.The specimens may be considered as representing the least favourable state of the water supply to the nictropolis during winter but still such as it may continue for several months in a wet season like the last. The temperature of the river at the time was 44' Fahr. The results are given in two forms first the acids and bases sepa- rately as actually found by analysis and secondly the same acids and bases arranged in the form of salts or chemically combined as they are believed to exist in the waters. The first group consists of waters not derived from the Thames. 1. ANALYSES OF THE NEW RIVER msrLONDON KEXT AND HAMPSTEAD WATERS. New River East London Kent Hampstead Water Water Water Water 1 1 1 Company.Companj-. Company. Company. Grains in a11 Imperial Gallon. A 7 Lime. . . . . . 5.7 192 6.9034 7.82 2.9160 Magnesia . . . . . 0.5280 0.7336 0.62 1.7098 Potassium . . . . . 0.4972 0-5600 0.35 1.6471 Sodium . . . . . 1-1634 0.9989 0.86 7-5761 Iron alumina and phosphates . trace 0.4560 trace trace Sulphuric acid (SO,) . . . 3.2550 2.5830 1-86 9.1702 Chlorine . . . . . 1.0500 1,0682 1.52 4.1230 Carbonic acid . . . . 11.1020 11.4527 11-56 10.9823 Silica . . . . 0.5005 0.6216 0.49 0.0728 Nitric acid . . . . 0.0150 0.4800 0.050 >t Ammonia . . .. trace trace trace trace SUPPLY OF WATER TO THE METROPOLIS. 2. ANALYSES OF THE NEW RIVER EAST LONDON KENT AND HAMPSTEAD WATERS.New River East London Kent Hampstead Water Water Water Water 1 1 1 Company. Company. Company. Company. Grains in an Imperial Gallon. 7 h 1 Carbonate of lime . . . 7-82 10.16 11.64 4.95 Sulphate of lime . . . 3.23 2-33 3.16 Nitrate of lime . . . . 0.02 0.72 dI07 Carbonate of magnesia . . 1.09 1-51 1%8 3.53 Chloride of sodium . . . 1-73 1.76 2.24 6.79 Sulphate of soda . . . 1.49 0.94 15.14 Chloride of potassium . . 0%6 Sulphate of potassa . . . ;I1 1 ;!25 1 iI40 Carbonate of potassa . . . 1.80 Silica . . . . dr50 d162 029 0.0 7 Iron alumina and phosphates . traces 0.47 traces traces Ammonia . . . . . traces traces traces traces Organic matter . . . . 2.79 4.12 2-61 1.84 Total . . . 19.78 23.88 21-08 35.59 Solid residue obtained on evapo-19-50 23-51 29.71 35.4 1 ration .. . . . Free carbonic acid in cubic inches 14.49 12-38 10.15 13.30 at 44O F. . . . . Free carbonic acid grains in a gal- 7.24 6.19 5.07 6.67 lon. . . . . . Suspended matter . . . 1*49 1-07 0.52 Degree of hardness (Clark’s scale) 14O.9 15O.O I6;;O 9O.8 The second group is composed of the Thanies waters. 1. ANALYSES OF THAMES WATERS. -Southwark Water Grand West 2g$ty and Vauxhall Lambeth taken at Junction Middlesex llear Company Company, Thames supplied supplied near supplied at Bitton. at Kew. at Barnes. Red-Houses Red-House Lambeth Battersea. Lime . 8.0046 7-4522 7.5390 7.5117 7.2751 6.7970 Magnesia . Potassium . . 0-6070 0.4261 0-5544 0,2769 0.5628 0.2185 0.5527 0.2821 0.6020 0.6048 0.701 1 0.4291 Sodium .. 0.4330 0-6127 0.7387 0.5784 0.7861 0.7805 Iron alumina and phosphates . Sulphuric acid . Chlorine . . 0.09’10 1.8782 0.9890 0.7630 2.6460 0.85 12 0.7630 3.0380 1.1424 0.2910 3.3005 1.2229 0.3430 2.4150 1.1725 0.8505 2.20 15 1.1746 Carbonic acid . 14.2170 11.9826 10.6260 10.6470 12*1100 12.8520 Silica. . . 0.6290 0.4466 1.0013 0.7189 0.7679 1.0451 Nitric acid. . 0.0180 trace trace trace 0,2360 trace Ammonia . . trace trace trace trace 0.0309 trace VOL. 1V.-NO. XVL. DD CHEMICAL REPORT ON THE 2. ANALYSES OF THAMES WATGRS. I West Southwark Water J:if$n Middiesex and Lambeth ~ ~ ~ Company, ~ taken at Company company ~ p ~ ~~~~~~~,~ at ;t Thames 1 supplied sup$ied Red-House supplied at Ditt"n at Kew.Battersea. Red House Lambeth. Battersea. Carbonateoflime . . i1 79 10.90 9 94 9 28 10.87 8 99' Sulphateof lime . . 3'06 3.26 4-23 5 61 3 05 2 99 Nitrateof lime . . 0.27 trace trace trace 0 95 trace Carbonate of magnesia . 1 27 1-17 1.16 1 05 1 29 1 44 Chloride of sodium . . 1.10 1'40 1.88 1.47 1 99 I 95 Sulphate of soda . . 0.18 I? Chloride of potassium . O'k7 0 ?5 ¶3 9 Sulphate of potassa. . 0.17 0'61 0:h 1.;4 0165 Silica . . . . 0.62 0.44 1-00 0% 076 104 Iron alumina and phos- phates . . . . 0.09 0.67 0.76 0.29 0-34 0.85 Ammonia. . . . trace trace trace trace 0.93 trace Organic matter . . 229 3.07 2.75 2 38 1-51 2 59 Total . . . 2 1 '33 21.70 22.75 2137 21 23 20 80 Solid residue found on evaporation . . .20.78 21 72 2267 2 t,28 21 08 20 40 Free carbonic acid in cubic inches at 44" F. 16 89 1346 11*56 12 30 13 57 16 64 Free carbonic acid grains in gallon . . . 8.25 6-73 5.75 6 15 6 78 882 Suspended matter . . ,I 0'01 0'02 1.92 1.15 9, Degree of hardness (Clark's scale) . . 14.22 14.00 14 60 144-1 15 00 14.16 The waters were all sensibly tinged of a yellow or ochry tint due chiefly to suspended clay with the exception of the Kent water which was clear and bright. This turbid condition of the waters was represented to us as having subsisted for two nionths but was rather on the decline at the time of observation. It was least marked in the Chelsea Grand Junction and West Middlesex waters which are filtered by the companies. These waters did not allow the suspended matter to fall entirely on standing in a glass jar but remained sensibly coloured after several weeks of rest ;they might all however we believe be perfectly clarified by the use of a properly constructed house-filter.The Thames Ditton water was taken from a main in Surbiton near the company's works at a later period of the season than the others namely on the 22nd of February and was clear and bright. It is a filtered water. The soluble organic matter from two of the Thames waters was subniitted to ultimate analysis and found tc give 0.105 grain of nitrogen in the Grand Junction Water and 0.031 grain of nitrogen in the Southmark and Vauxhall Water. The existence of nitrogen is generally supposed to iinply the animal origin of organic matter and on such evidence a minute and probably unimportant portion of animal organic matter would be admitted to be present.SUPPLY OF WATER TO THE METROPOLIS. 381 None of the waters had any marked taste or odour nor betrayed any indication of putrescence either when first taken up or after being kept in bottles for several weeks at a temperature between 50’ and 60’; nor even after remaining in close vessels for two weeks at 80’. In these waters when submitted to microscopic examination no ani-malcules were observed in any case. But the period of the year was not that at which any considerable developruent of animal life is to be looked for. All the waters under consideration have much of a common charac- ter arising from the similar geological conditions of their sourccs.Every one of them is derived in a great proportion from the Chalk Formation of which the waters have peculiar properties. This appears both in the degree and the nature of the bardiiess they exhibit which is due to the presence of salts of lime arid magnesia in solution It may be useful to distinguish the quality known as the (‘hardness” of water according as it is of a temporary or permanent character. Perfectly pure or soft water when exposed to contact with chalk (carbonate of lime) is capable of dissolving only a very minute quantity of that substance; one gallon a€water in weight equal to 70,000 grains taking up no more than 2 grains of carbonate of lime. This earthy impregnation is said to give the water 2 degrees of hardness.But waters are often found containing a much larger quantity of carbonate of lime such as 12 16 or even 20 grains and upwards in the gallon. In such cases the true solvcnt of the carbonate of lime or at least of the excess above 2 grains is carbonic acid gas which is found to some extcnt in all natural waters. But this gas may be driven off by boiling the water and the whole carbonate of lime then precipitates in consequence or falls out of the water with the exception of the 2 grains which are held in solution by the water itself. The gas- dissolved carbonate of lime gives therefore temporary hardness curable by boiling the water. An artificially prepared hard water containing 13b grains of carbonate of lime to the gallon was observed to decrease from 13.5 to 11.2 de5rces of hardness merely by heating it in a kettle to the boiling point.Boiling for five minutes reduced the hardness to 6.3 degrees fifteen minutes to 4.4 degrees thirty minutes to ,206 degrees and one hour to 2.4 degrees. The softening effect of boiling does not tlierefore appear all at once but the greatest proportional effect is certainly produced by the first five minutes’ boiling. The West Middlesex and New River waters were both found to soften by boiling very much in the same manner as the preceding pure chalk water except that the ultiniate hardness of the two waters specified was somewhat DD 2 CHEMICAL REPORT ON THE higher. By an hour’s boiling the West Middlesex fell frorii 14.6 to 5.5 degrees and the Sew River from 14.7 to 4.1 degrees.Other salts of lime such as sulphate of lime are generally dis- solved in water without the intervention of carbonic acid gas and therefore remain in solution although the water is boiled imparting perrnunent hardness. The shallow wells in the gravel all round London are permanently hard to the extent of 15 degrees and upwards from the presence of earthy sulphate and contrast dis-advantageously in this respect with the river waters. ’The carbonate of lime in water deconiposes about ten times its weight of soap in washing (more exactly 8.8 white curd soap and 10.7’ common yellow soap) and other salts of lime act injuriously upon soap in proportion to the lime they contain; the soluble soap con- taining soda being converted into an insoluble and useless compound containing lime.The water is then deprived of lime or softened at the expense of the soap. The lime in 100 gallons of Thanies or of New River Water thus occasions the destruction of about 34 ounces of soap before any portion of it becomesavailable as a detergent. By the experiment of adding measured quantities of a solution of soap to a certain measure of any water to be examined till the soap begins to give a lather with the water or soap bubbles appear on the surface on agitation the proportion of earthy salt or degree of hardness may bc ascertained ;thc method generally followed in the experiment being that directed by Dr. Clark. The hardness was remarl;ably uniform in the water of the eight principal Metropolitan Water Compmies ;the Hainpstead water which is locally peculiar and amounts only to about 1 per cent of the whole metropolitan supply being withdrawn from the com- parison.The degrees of hardness by Clark’s soap test of the waters of the eight principal London Companies observed on the 29th 30th and 31st of January were as follows Grand Junction ......14O.O West Middlesex ......14O.6 ....15O.O .......14O-4 Lambeth .......14O-2 Lambeth (from Thames Ditton March 8) I .14O.2 From other New River .......140.9 sources than I East London .......15O.O the Thames. Kent . . .....140.0 The variation observed in this property is from 14O to ’45O or one degree only. It appears also from observations made at dif-ferent seasons that this range is not considerably exceeded at any period of the year except during floods when the hardness of Thames water may fall to 8 or 9 degrees.The general qualities of the present water supply deduced from SUPPLY OF WATER TO THE METROPOLIS. observation of its ordinary properties as well as from chemical analysis may be thus enumerated 1. The effect of ordinary filtration through sand is very decided on Thames water as it appears to be upon chalk waters in general. The river water can thus be easily obtained unless in certain excep- tional circumstances entirely free from suspended solid matter or mechanical impurities. 2. When in good condition the Thames water also possesses the peculiar and agreeable brightness of chalk waters arising from the entire absence of colour combined also usually with good aeration.3. The Thames water may be described ,to be in ciscum-stances not unfavourable to purity and coolness a palatable water. The amount and nature of its saline constituents probably contribute to its general acceptability as a beverage. 4 It may be safely stated that no sufficient grounds exist for believing that the mineral contents of the water supplied to London are injurious to health. No rearonable doubt indeed can be enter- tained of its salubrity. The shallow well-waters of London vary from 32to 80 degrees of hardness yet these waters have never been pronounced unwholesome. An aerated water is manufactured and safely consumed to some extent which contains 92 grains of car- bonate of lime to the gallon instead of 12 or 14 grains as in Thames water.The portion of lime and magnesian salts in the water drunk must indeed be greatly exceeded in general by the quantity of the same salts which enters the system in solid food. The only obser- vations from which an interference of the lime in water in deranging the processes of digestion and assimilation in susceptible constitutions has been conjecturally inferred have been made upon waters con- taining much sulphate of lime and magnesia as the Brighton shallow well-water or the hard selenitic water of the New Red Sandstone and have no force as applied to the Thames and its kindred waters as the earths exist in these principally in the form of carbonate.5. The water at present supplied may be circulated through leaden pipes or preserved in leaden cisterm with an unusual degree of safety. The corrosion of water cisterns in London is generally occasioned by the mud which subsides to the bottom particularly when the sediment includes organic matter and the evil might be greatly diminished by more frequently cleaning out the cisterns. But it is to be particularly remarked that this corrosion is not attended by any sensible solution of lead in the water and that the water of the cistern is not poisoned in consequence. The London water may indeed be said to exert the least degree of solvent action upon lead. To the nature of the action of different waters on this metal there will be occasion again to refer.The circulating system of iron pipes appears also to receive a cer- tain amount of protection from the alkaline character of the present CHEMICAL REPORT ON THE supply. The erosions and bulky deposits in cast-iron pipes which have given great trouble in the distribution of certain waters are quite unknown in London. 6. Putrefactive decomposition appears also to occur less rapidly in hard than in soft water and hard water seems to be the more easily preserved in reservoirs or tanks without deterioration for a short time. 7. Finally all these advantages of the present sources are en-hanced by the circumstance that the attainable supply from the Thames is of remarkable uniformity and may be said to be unlimited.The average volume of water which passes Richmond daily is calcuo lated at 800,000,000 gallons and the minimum at 600,000,000 gallons the last amount being twelve times the present consumption of the metropolis estimating the latter at 50,000,000 gallons. Although not fed by a great lake both the Thames and the Lea are largely supplied from spongy chalk strata which possess an enor- uious water-capacity and answer the purpose of an equalizing reser- voir the discharge of water from these beds being nearly indepen- dent of the seasoil. This must be of great service during the hot summer months when the quality of many rivers which depend chiefly on surface supply beconies much deteriorated from the effect of evaporation and the accumulation of soluble vegetable matter.Against these grounds of commendation certain disadvan taps of the present supply are to be placed. 1. The fluctuating temperature of the present supply in which it resembles all river and surface-drainage water. The temperature of the Thames at Greenwich was observed by Mr. Glaisher to exhibit the following high range during the warm montlis of 1846 In June from 71O.9 to 73O Fahr. In July from 6CiO.l to 67O.4 Fahr. In August from 66O.7 to 68O.3 Fahr. During the months of June July arid August the temperature of the water supplied to the inhabitants of London is said to be gene- rally above 65O and sonietimes above 7O0. This loss of coolness in itself makes the water greatly less palatable while it promotes the decomposition of organic matter which farther impairs the quality of the water.2. Like rivers generally the Thames is liable to turbidity from floods. It then acquires a yellow colour well known as the flood tinge which is of an unusually persistent character and only very partially removed by sand-filtration. We agree with engineers who have had the fullest means of observation in considering that so much of this discolouration is due to the compound of clay and organic matter washed out by the Brent from the extensive and highly manured field of tlie London Clay Formation which it drains SUPPLY OF WATER TO THE METROPOLIS. as to make it an object to draw the London supply from a point above the embouchure of that tributary of the Thames at Brentford.This clay tinge which resists the action of acids and does not even fall down with carbonate of lime precipitated in the water is known to be removable by alum. We were informed by an officer of one of the companies that seven grains of alum per gallon of water would be sufficient in general to precipitate the clay com- pletely and to produce a perfect discolouration The alumina is itself entirely removed but sulphuric acid is introduced which by con-verting carbonate of lime into sulphate would induce a hardness permanent on boiling. In floods also the water often tastes dis- agreeably of vegetable matter. 3. Allied to this mineral discolouration is the colour and contami- nation to which the river is more particularly liable in the latter part of autumn and early months of winter from the extensive decompo- sition of vegetable matter in the highly cultivated district through which it flows.This is one of the disadvantages which the Thames shares with all rivers which do not originate in a barren non-retentive soil such as the millstone grit of Lancashire and which cannot be collected for town supply near their sources. The evil often admits of being greatly reduced by collecting from a restricted area and storing the excess of floods in vast reservoirs as in the new gathering grounds of several towns in Lancashire and the wcst of Scotland. These reser- voirs however must be deep with an impervious bottom; and the nature and configuration of the surface afford facilities for their con- struction in hilly districts which are not to be found in the valley of the Thames.For the present London supply this contamination is a serious evil. 4. As the main drain of a large and populous district the Thames becomes at all seasons polluted by the sewerage of several considerable towns and by the surface drainage of manured and ploughed land. Even above Kingston a population of three-quarters of a million is found upon the banks of this river and its tributaries. The diverting the sewerage of the various towns entirely from the Thames would be attended with so much difficulty that the project need not be taken into account. At the same time we doubt whether the existence of organic contamination from town drainage is at present perceptible in thc Thames above the reach of the tidal flow or amounts there to a sensible evil.The indefinite dilution of such matters in the vast volume of the well aerated stream is likely to lead to their destruction by oxidation and to cause their disappearance. The river may reasonably be supposed to possess in its self-purifying power the means of recovery from an amount of contaminating injury equal to what it is at present exposed to in its highcr section. The contamination by scwerage however cannot fail to become considerable and offensive with the increase of population and the more 386 CHEMICAL REPORT ON THE eEcient and general drainage of towns. And it appears to beonly a question of time when the sense of this violation of the river purity will decide the public mind to the entire abandonment of the Thames as a source of supply unless indecd artificial means of purification be de- vised in the meantime and applied.With reference to the possible supply of the metropolis from the upper section of the Thames it may here be stated that a main of thirty inches in diameter is already laid for conducting water from Thames Ditton to Lambeth capable of conveying from eight to ten million gallons daily; while arrangements are made along the whole distance for placing three additional similar pipes when required ; a provision which would supply double the quantity of water now taken from the river within the tidal flow by all the existing Thames Companies.The tomn-drainage below Richmond and above the tidal return from London if at present inconsiderable cannot be calculated to continue so owing to the rapid extension of the metropolis in the great lines of Bayswater Kensington and Wandsworth. The supply of the New River and East London Companies from the Lea has all the good qualities which have been ascribed to the Thanics water to which in its mineral constituents it is essentially similar while it appears less affected by turbidity from floods. The objectioiiable impregnations from town-drainage are also in- considerable in the supply of the first of these companies. Farther it is proposed by the River Lea Navigation Trustees to divert the town-drainage of the New Ever district particularly that of Hert- ford to a point on the Lea below Ware.It has already been stated that none of the Companies’ waters when taken up in January gave at the time or two weeks after- wards when kept at either the actual temperature or at 80° any marked indication of putrescence to the smell or taste. The complaint on this ground is mainly to be referred to the filthy condition of the cisterns butts and other vessels in which the water is preserved in private houses and is only attributable to the water companies in so far as they necessitate the use of such recep- tacles by furnishing an intermittent instead of a constant supply of water. It is to be feared however from the result of concurrent testimony that the water does occasionally come into the houses tainted with decaying animal or vegetable matter.We have been informed for instance on good authority that in a warm summer the New River water as delivered in London sometimes contains spawn floating in it and has a fishy smell which is objected to by bathers; but this matter and all animalcules visible to the naked eye may be detained by sand filtration and the nuisance in this instance is to be ascribed to the omission of that practice. Although according to chemical analysis the organic matter never SUPPLY OF WATER TO THE METROPOLIS. appears to rise in the water of the Companies who filter to a pro-portion by weight which need excite alarm or would appear extra-ordinary to the chemist and although it may be impossible to ascertain its origin still the balance of evidence appears adverse to the conclusion that what is known to enter is immediately de- stroyed.No marked increase in the proportion of nitric acid is observed in the Thames within the limits of the metropolis which might be expected to mark the destruction by oxidation of much azotized animal matter if it really took place; while the rapid pro- duction of animalcules in Thames water when aided by light and warmth although not in itself a source of danger evinces the abun- dant presence of organic matter which if not rapidly assimilated by these lower orders of animal beings might render the liquid repulsive arid in all probability actively injurious to the human constitution. The antiputrescent property of Thames water which it acquires from its hardness is opposed to the immediate destruction of organic impurities and is perhaps more valuable as adapting the river to the transport and removal of such matters than for preserving the water in a condi- tion suitable for drinking.If the Thames should continue to be the source of any considerable share of water supply it must be desirable therefore to draw it at a point removed from this contarni- nation and entirely above the tidal flow of the river. The disco- louration from the turbid floods of the Brent would at the same time be avoided by proceeding higher up than the Teddington. weir. But it will be asked may not any change soon cease to Be required on such grounds when the Thames is relieved of the London sewerage as it is anticipated that the river will be in a few years? The removal of the nuisance complained of however can never be complete but only partial.The contamination from navigation and the river population must be increasing rather than otherwise ; while gas-works and other indispensable chemical manufactories which at present pour their refuse products directly into the river would necessarily continue to do so as these products are often of a kind not admissible into ordinary sewers. 5. The hardness of the metropolitan water-supply which is due to its mineral constituents may be considered as the sanie whether derived from the Thames or the Lea and amounts on an average to about 14 degrees. Although this degree of hardness is considerable and highly objectionable still it is exceeded by the hardacss of pure chalk waters such as are supplied by water companies to the towns of Gravesend Dover and Brighton and which may be estimated at from 18 to 20 degrees.The deposit which Thames water gives rise to in boilers is also friable and less coherent than the stony deposit from selenitic waters; and means exist such as the use of sal ammo- iliac for entirely preventing the occurrence in steam boilers of deposit from chalk but not from selenitic waters. CH$MICAL REPORT ON THE The hardness of the London water is also of the least objection- able kind being chiefly as has been already stated temporary hard- ness which is removed by boiling. The whole 14 degrees of hardness can be ascribed only to that portion of the water which is used cold.To ascertain the average state of hardness of heated water portions of water were drawn on six different occasions from the fixed boiler of a kitchen range supplied with New River water; the hardness was found to be 5.4 4.9 4.1,4.1 4.9 and 5.3 degrees of which the mean is 4.8degrees. The hardness of London water as it is commonly used after boiling appears therefore to be about 5 de-grees while without heating it amounts to 14 degrees. The distinc- tion between permanent and temporary hardness was illustrated to us at Greenwich where the brewer described the deep well-water of the Hospital (which is only occasionally pumped up) as a soft water although its hardness is 21 degrees; but it is only used by him for mash- ing after being boiled when being a pure chalk water its hardness is reduced to about 4 degrees.The importance of this distinction was likewise shown though in another manner at Whitehaven where a great and apparently disproportionate advantage has been experienced from a change in the town supply from a water which we found to be of 6.7 degrees of hardness to another water of 1.4 degrees. The hardness of the former water however although not great in amount proved to be of the permanent description; as after an hotir’s boiling the water of the old supply was still of 6.4 degrees that is harder than even Thames water is after boiling. The hardness of the former town supply in Lancashire although often inconsiderable was generally of the same permanent character as the old Whitehaven supply.The hardness of‘ water forms an objection to its use both in cooking and mashing but the force of the objection to the Thames water for culinary purposes is much diminished by the large amount to which that water is softened by boiling. Tea is pre- pared in London with water which it appears is practically of only 5 degrees of hardness. It appears impossible to obtain any standard or test by which the strength of an infusion of tea can be expressed in numbers or to find any means of judging of its quality more precise than the indications of taste. On carefully comparing infu- sions prepared as for family use of an equal quantity of tea in the New River water before described which averaged about 5 degrees of hardness and in water of 2.4 degrees only the observation made on several different occasions was that the inequality in strength and flavour of the two infusions was altogether iiisensible to some palates.But an increase in the bitterness was more generally remarked in the soft water infusion without enhancement of flavour. Where a pre- ference was expressed it was in favour of the quality of the hard water infusion but the difference between the two infusions was not considered material by any one. SUPPLY OF WATER TO THE METROPOLIS. Hard water is disadvantageous for making tea chiefly it appears by requiring the heat to be longer maintained in preparing the infusion. Tea is habitually made of excellent quality and with economy in some families by means of spring water of a high degree of permanent hardness but then the infusion is con-tinued for half an hour and the temperature maintained near the boiling point during that period.The tea for the Greenwich pensioners is infused in a large copper surrounded by a steam case with water from a well in the superficial gravel of 24 degrees of hardness of which 18.6 degrees are permanent. But in the private residences adjoining it is found necessary to use carbonate of soda for softening with the same water in the absence of the efficient means of infusing described. Where any great loss of strength of the tea infusion has been observed in passing from a soft to a harder water it may be probably referred to the circumstance that the mode of infusing has not been properly adapted to the hard water.The use of hard water must on this account be attended with a frequent waste of tea. The rapid process of infusion generally employed in London indicates the use of a comparatively soft water. Tbe water to which M. Soyer gave a preference for tea-making even over distilled water in experiments reported to the General Board of Health was the London deep well- water. This is usually softer than Thames water after boiling and contains in addition a sensible quantity of carbonate of soda to which its superiority is probably due in part. The water of the Trafalgar Square deep well has an original hardness of 5.4 degrees which is reduced to 1.1 degree by boiling.No great objection can be taken to the use of the London water for other culinary pur- poses. The presence of much sulphate of lime in water makes it unsuitable for cooking vegetables owing to the tendency of that salt to form an insoluble compound with their legumine but this effect is insensible with Thamcs water. The injury sustained in washing from the hardness of the present water supply is greatly more important but the estimation of its amount is difficult and involves the consideration of a variety of circumstances. The softer the water the better is it adapted for washing with soap; the earthy salts present causing a definite and calculable loss of soap which may be taken as amounting with every gallon of water used in washing to 10 grains of soap for each degree of hardness of the water.Thus with one gallon of Thames water at 14 degrees of hardness before boiling the loss of soap would be 140 grains and at 5 degrees of hardness after boiling the loss of soap would be 50 grains; or with 100 gallons of water the loss in the first case would be 32 ounces and in the second about 11Tt; ounces. But such data are not alone sufficient for calculating the saving of soap effected CHEMICAL REPORT ON THE by the use of a soft over a hard water. For soap is used in washing not merely in quantity sufficient to soften the water but in excess to act as a detergent. The problem is to determine how great the portion of soap lost in softening is compared with the portion profitably used for washing in the softened water.Such data however are not easily obtained. In the bleaching of white goods as scientifically pursued soap is not made use of; the process being a series of operations in which the cloth is exposed to lime- water carbonate of soda chloride of lime and acid. The only practice in cotton manufactories where quantities are exactly noted analogous to common washing is the soaping of dyed goods. We have found seven pounds of curd soap then used with 250 gallons of water which is nearly 45 ounces of soap for 100 gallons of water. Now if this water were of 14 degrees of hardness 32 ounces more of soap would be required for softening; and of the whole 77 ounces consumed 45 ounces would be available and 32 lost which is a sacrifice of nearly 42 per cent of the soap.n'ith boiled Thames water of 5 degrees of hardness 113 ounces would be required for softening with the 45 for washing making 564 ounces together of which 114 ounces or about 20 per cent of the whole soap is wasted. In the washing of woollens we find water employed with so much as ,',th part of its weight of soap that is 200 ounces of soap with 100 gallons of water. Here the loss of soap by wing water of the two different degrees of hardness referred to being constantly 32 and 116 ounces would form a much smaller proportion of the whole soap consumed than before namely about 14 per cent in the one case and 5 per cent in the other. The maximum loss of soap by the use of Thames water employed cold would therefore be estimated from such data at 42 per cent of the soap employed with linens and 14 per cent with woollens; or when the same water is softened by boiling at 20 per cent with linens and 5 per cent with woollens.With woollens the loss is too small to entitle it to further consider- ation particularly when it is also known that the proportion of woollen articles washed is very small with the poorer classes who frequent the public washhouses; not more it is believed than two or three per cent of their whole washing. Nor is it to be supposed that in the washing of linen a loss of 42 per cent of soap is necessarily sustained in all cases. Carbonate of soda is generally employed by laundresses in London to soften water for washing.Indeed this salt is used in the public washhouses in a considerably larger proportion than is necessary to precipitate the hardening salts of lime on its own account as a powerful detergent particularly in the first boiling of the linen and is not omitted although the water is soft as with the Trafalgar Squarewater used in the St. Martin's public washhouses. This use of soda does SUPPLY OF WATER TO THE METROPOJ,IS. 391 not appear to be attended by any injury to the linen with the excel- lent means of wringing by which the discoloured water is got rid of and the abundant supply of cold water for rinsing which are provided in these establishments. The proportion of dyed articles washed by the poor is small and the colours are generally of a permanent kind which resist soda.In all their washing of woollens and coloured cottons as well as white cottons soda is in consequence equally used. The following opinion of Mr. W. Hawes is recorded in the evidence upon this subject collected by the General Board of Health that ‘‘Since the manufacture of crystals of soda at a very low price and its almost universal use in washing the waste of soap from washing in hard water has been very trifling. The quantity of soda used to soften water as it is called is a source of expense but of a trifling amount.” This appears to be strictly true at least of the washing of the poorer classes as conducted in the public washhouses. In regard to the extraordinary injury and wear of linen from London washing often observed and which has been ascribed to the hardness of the water it may be remarked that no such injury to the linen occurs in many private laundries where hand-washing only is prac- tised and the use of chloride of lime and acids entirely avoided.It is most marked in the larger establishments where much of the washing of the metropolis is conducted. It is in the more careful washing for the middle and upper classes that the advantagcs of soft water become fully sensible. In the digestion of the linen in hot water with soap and carbonate of soda preliminary to the proper washing the hardness of the water can only occasion a trifling loss of soda; but afterwards in the wash-tub where soda is avoided the earthy salts must occasion a loss of their full equivalent of soap.It is found proper also to avoid boiling any portion of the Thames water that is used in the wash-tub or even heating that water above a certain point for the carbonate of lime precipitates 011 the linen carrying down the colouring matter of the water with it and producing stains which there is the greatest difficulty in afterwards removing from the linen. The colour from the water is thus indeed fixed upon the cloth by the precipitated lime with the tenacity of a mordant. The evil of the hardness of the water is therefore aggravated by the flood-tinge or clay-colour which the London waters often exhibit for several months in the year. . The number of gallons of water generally used with a certain weight of soap appears also to be considerably greater in London washing than in the practice of the Lancashire bleachers so that the waste of soap from hardness cannot fall below but may exceed the previous estimate.In the washing of the person the saving of soap by the use of soft water is most obvious. For baths soft water is most agreeable CHEMICAL REPORT ON THE and beneficial and might contribute greatly to their more general use. Its superior efficiency to hard water in washing floors and walls is calculated also to promote a greater cleanliness in the dwellings of all classes both within doors and externally. While in the occasional domestic washing of linen the smaller preparation necessary for washing in soft compared with hard water the saving of soap which would then be sensible to its full extent and the more easy and agreeable nature of the operation would make a supply of soft water in a high degree desirable.The use of soda in washing would be gladly avoided by most housekeepers owing to its injurious action on the colours of certain prints and the permanent yellow tinge and weakness of fibre which it may occasion even in white linens when exposed to heat before the soda is entirely washed out as in ironing. A strong desire exists to avoid its use and where soda is avoided there is no doubt that a saving of about one-third of the soap would be made by washing linen in water entirely soft; supposing the comparison to be made with water of the ordi- nary hardness of the London supply but of which one-third part was previously softened by boiling.The saving in labour would be even more considerable if the cornparison be still made between washing in soft water and washing in hard water without the aid of soda. 2.-OF THE IMPROVEMENT OF THE PRESENT WATER SUPPLY. A portion of the present water supply might no doubt be improved at times by submitting it to sand-filtration. The necessity for this process niay be greatly diminished by the use of extensive subsiding reservoirs such as the New River and East London Companies pos- sess but filtration can never be entirely superseded being indispen- sable as the concluding a.peration of purification to remove the vegetations and accidental impurities which may gain access to the clearest water by exposure during several days as well as to correct original turbidity.But the insufficiency of sand-filtration alone to clarify .cT;ater which flows from clay land particularly at the season when the water is charged with decaying vegetable matter is obvious at times in the best filtered Thames water. Many waters of considerable softness such as the Medway and those of the Weald of Kent must be excluded entirely on this account as sources of an improved supply. We doubt even whether a perfect discolouration could be comniandect by filtration either of the Ilea and its higher tributaries or of the Thames above Kingston unless provision were made in both eases for the exclusion of flood-water. The matters dissolved in water have been obscrved to diminish in particular circumstances aftcr sand filtration.But any chemical SUPPLY OF WATER TO THE METROPOLIS. action which a sand-filter may exercise is Boon exhausted and it would be unsafe to calculate upon advantage from it in practice. Professor Way's observation of the power of certaiu clays and loams to remove much organic and saline matter from solution is well established but this property does not appear to admit of being applied to the rapid filtration of water in reservoirs. Other means of improvement of the present supply have been brought before us and engaged much of our attention namely the removal of carbonate of lime from water with a portion of the organic and colouring matter by adding to it a proper quantity of caustic lime as proposed by Professor Clark either in the form of lime-water or of the dry hydrate of lime.* Carbonate of litne being held in solution by the free carbonic acid gas dissolved in water is precipitated by boiling which expels the gas as already stated and may be precipitated by removing the same gas in any other way.Accordingly caustic lime when added to hard water in sufficient quan- tity to neutralize the carbonic acid removes the solvent and becom- ing at the same time carbonate of lime must precipitate together with that originally in solution. The operation of tliis process was first witnessed by us at the Mayfield Print-works in Lancashire where 300,000 gallons of water are submitted to it daily at a trifling expense and with little trouble but inore for the purpose of' discolouration than softening.A careful series of experiments made in the Laboratory left no doubt on our minds that the means of conducting this process are certain in their results and suf€iciently simple to be left to the execution of a workman of ordinary intelli- gence. The precipitation of the c,>rbonate of lime was terminated within twenty-four hours and the water if free from turbidity before the liming continued in that state but if originally turbid it re-mained so and required filtration besides the liming to make it clear. The New River and Thames waters were softened in this way to an average of about 39 degrees of hardness or to a lower point than by an hour's boiling.More important trials of this process upon the large scale were after- wards witnessed by us at the Chelsca Water Works which were con- ducted under the immediate superintendence of M r. James Simpson Jun. the Resident Engineer. The usual supply of water pumped up froni the river was run into the first reservoir in company with a small stream of milk of lime flowing from a wooden cistern in which the powder of slaked lime was mixed with water and kept in suspension by stirring. The intermingled streams passed on into one of' the great settling reservoirs to the extent of from 3,000,000 to 4,000,000 gal-lons which is nearly a day's supply. The only precaution taken to insure the absence of any excess of caustic lime consisted in testing the water in the settling reservoir by a drop of nitrate of silver * Repertory of Patent Inventions October 1841.394 CIIERIICAL REPORT ON THE which shows if the quantity of lime required has been exceeded by the brown colour of the precipitate then formed. After subsiding generally for twenty-fours or longer the water was finally passed through the OP-dinary sand-filters before being distributed. The degree of hardness before and after the softening process in five such experiments was reported to us by Mr. Simpson as follows with the appended remarks THAMES WATER AT THE CHELSEA WATER-WORKS. Degrees of Hardness. 1851. Before Liming. After Liming Remarks. February 24 . . 14.0 4.5 The river was in good condition. The mixing was completed in 10 hours.March 1 . . . March 18. . . March 22. . . 14.1 10.5 11.6 3.75 5 4.8 { { { The river was in good condition. The mixing in 98 hours. The river in flood. The flood Recovering from flood. Yellow tinge retained after liming. flood tinge not removed. April 17 . . . 15.5 3.6 River in an average condition. The conclusions which were come to both by the engineer and ourselves from these experiments in which the operation had not the advantage of the efficient means of mixing which might be intro- duced where it was permanently adopted were that the process falls easily into the routine operations of water-works and is not attended with any peculiar difficulty on the large scale; and that the softening of Thames water in its ordinary condition by this process to a point under 4 degrees of hardness is perfectly practicable.The water of the experiment of the 17th of April was analysed before and after the softening operation. The whole fixed constituents contained in one gallon of water were found to be re2uced from 24.07 to 8-31 grains and the organic matter from 2.50 to 1.60 grains; at the same time that the quantity of lime-salt present (considering it all as carbonate) was reduced from 13.65 to 2.63 grains. The softened water was clear and bright had acquired no odour nor taste from the process and could not be distinguished in its sensible qualities from pure spring water of equal softness. The average cost of' the application of the process in the five experiments was 12. 6s. 2d. for one million gallons of water; of which almost exactly one-third was for labour and two-thirds for lime the latter costing 1s.per cwt. Mr. Simpson believes however that it may be reduced and that 20s. for one million gallons would be a more proper general estimate. The influence which this ad&- SUPPLY OF WATER TO THE METROPOLIS. tion to the cost might have upon the price of water may be gathere from the following returns lately made to the General Board of Health of the present cost to each water company of one million gallons of water FIRST COST OF ONE MILLION GALLONS OF WATER. S. s. d. New River ....... 9174 East London ....... 677& Southwark ...* I). * 594 West Middlesex ......1697 Larnbeth .......15064 Chelsea . ......191044 Grand Junction ......914 64 Kent ........172107f Hampstead ....... 22570 Average (about) ...SlO 10 94 The average charge of the companies is by the same return about sixpence for 1000 gallons or 251. for one million gallons. The softening process would therefore add about 10 per cent to the original cost of the water or 4per cent to the price charged to the consumers. Thames water appears always to be divested of a certain quantity of both organic aiid colouring matter by this process so that its purifying influence greatly exceeds that of sand filtration. It cannot however be expected to exhaust the whole organic matter and might therefore leave certain soluble sewerage products untouched. Moreover it does not supersede the necessity for sand filtration ;for the subsidence of the precipitated chalk and the spontaneous clearing of the water by rest after the liming appear only to be complete when the water has been filtered beforehand or is so bright as not to require filtration.The suspended chalk may however be always removed by sand filtration and being highly crystalline and granular it does not choke up or act injuriously upon filters. The experience of eight months at Mayfield was quite decisive that sand filters are not injured by superadding the lime-process but only require to be more frequently cleaned from the greater deposit on their surface. The liming process even when combined with filtration proved to be unequal to remove the yellow flood-tinge of Thames water nor did it appear to abate an objectionable taste of vegetable matter which the water also then possessed.Wad the result been different the grounds for the adoption of the softening process would have been most cogent. But it seems that it is not to river-waters that this elegaut and useful purifying process is most advantageously applicable. VOL. IV.-NO. XVI. EE CHEMICAL KEH’OItT ON THE 3.-OF THE SUPPLY RECOMMENDED BY THE BOARD OF HEALTH. For information respecting the new sources of supply which have been proposed to the General Board of Health the Commissioners were referred by the Board to the Hon. William Napier with whom they accordingly conimuiiicated on the subject. They were farther supplied with the printed Reports of that gentleman’s in- vestigations which have been communicated by him to the Board at different times up to April 10 1851; with the Report of the Board’s Engineer Mr.Rammell of his examinations and gaugings of the sources recommended dated November 9 1850; and the Report made to the ‘‘ Metropolitan Sanitary Water Company,” by Mr. J. F. Bateman C.E. with a Table exhibiting the result of the gaugings of certain streanis on the proposed gathering grounds by Mr. Joseph Quick C.E. The Commissioners were favoured with the assistance of Mr. Napier who accornpanied them over the district of the Hindhead to the south of Guildford in Surrey on the 14th and 15th of February last when the most important spring-heads or sources were visited and specimens of the water taken up for chemical examination.This is a pretty well defined district including the water shed on all sides of an elevated tract belonging to the Green Sand formation and known as the Hindhead over the summit level of which the post road to Portsmouth is carried for several miles. The area contains about 35 square miles and is divided into pretty equal parts by the road. To this area we understood Mr. Napier to look for nearly three-fifths of his proposed supply and that it was considered as rather a superior gathering ground to the larger field of the Bagshot sands which is included in his plan the sources in the latter quarter being similar in character but more dispersed. A portion of the latter field which lies near Farnham was also visited by the Cornmissioners on the 13th of March and specimens were taken of the soft water with which that town is supplied and which is of peculiar interest as it comes from the proposed gathering grounds The analysis of the Farnham water and six selected springs from the Hindhead gave the following results ...... Ya ....-g.. .. w e a .v........... .....ii. ... fD % m ............ .....m..*. ............. .......... Farnham Farnham. Water. Spring flowing Spring flowing into Sweet Water Into Sweet Water Witley. Witley. Critchmere Critchmere Springs. Springs. -Vellwool near Vellwool 16miles Haslemere. from Haslemere. The Punch-bowl The Punch-bowl Y’000. 00.0 YO“ near the summit wo-o“ OW” W’ ecn-near the summit ohiow 4-cp 0 ow of the Hindhead.of the Hindliead. Barford Mill-Barford Mill-stream. stream. Spring at the Spring at the Moors Cosford Moors Cosford House. House. CHEhITC‘AL REPORT ON THE entirely unexceptionable in point of aeration and colour. Their usual temperature when taken up was from 50° to 52O showing that their sources are deep seated and preserve the average temperature of the whole year. Their taste betrayed no organic taint but evinced great purity although they appeared rather flavourless and somewhat vapid to persons habituated to the use of hard water. Their hard- ness proved extremely low except that of the spring at the Moors near Cosford House which was of 10.8 degrees of hardness but this is evidently a water of a different character from the others and may be excluded from the comparison at present.Degrees of hardness of the Surrey waters Farnham . . 2.27 Spring flowing into Sweet-water pond Witley Critchmere springs . Vellwool near Haslernere . . . . 1 *95 1-86 1-86 The Punch Bowl Hindhead . . 2-45 Spring at Barford mill . . 2.70 Average hardness . 2-18 These springs therefore exhibit an average hardness of little more than 2 degrces. The value of this extreme purity and softness is not diminished by the other mineral and organic constituents of the waters which are insignificant in quantity and really of no account. ‘I’he nearly entire absence of carbonic acid from these waters to which attention has been drawn by Nr.Napier is perhaps their most singular chemical feature. The question however arises how far these springs represent the large supply of upwards of 20,000,000 gallons which it is proposed to draw from this district. The visible springs are not very numerous nor did the yield of each appear very great. The water from the largest might be carried off by a two-inch pipe. It is proposed “to lead away the deep springs only,” excluding “the shallow land-springs and surface-drainage.” The possibility however of keeping these different waters separate appeared to us extremely doubtful. The high ground consists entirely of beds of siliceous sand rarely indurated to any extent or converted into sandstone which constitute enormous storing reservoirs for the springs.The springs are at all levels and a partial outflow of water may take place at any point on the declivities and is not determined to a certain line either horizontal or vertical by the occurrence of a retentive stratum such as a bed of clay or rock along the outcrop of which spring water might be collected. Hence the slightest cause may occasion the loss of a spring and its reappearance at another point of lower level. From few or none of these springs can the flow be SUPPLY OF WATER TO THE METROPOLIS. accurately gauged andit was not attempted by the Board’s engineer Mr. Rammell. Tothe gauging of the small streams or rivulets even Mr. Kammell observes “ an insuperable obstacle” was found “in the porous nature of the beds of the streams which rendered all attempts to intercept or divert the whole of the flow hopeless.From this cause it was quite impracticable either to dam up the water effectually or to lead it along an artificial channel laid at a less inclination for discharge into the box (in which the water was to be measured). Most of the smaller streams have beds of perfectly clean gravel through which on the current being arrested escape immediately takes place. It appeared indeed on close examination that even the ordinary run of these streams is not wholly over or above the surface but partly within the bed of the channel itself much of the water thus passing away insensibly between the pebbles. Any attempt to dam up these streams with a view to gauging over a weir must have failed from the same cause.” The bottoms and sides of the springs are equallyporous.A certain proportion also of the springs from which the supply is to be derived are situated in the beds of streams and at the bottom of ponds into which the streams expand in their course. The mode suggested to us by which these last springs could be reached and their supply kept apart from the rivulet flowing above was by a species of deep drainage which it was intended might carry away the water of the springs while the surface water and ordinary field drainage wonld be carried off in another retentive conduit so as to prevent the latter water from sinking into the sands and afterwards appearing as a spring. at a lower level. Into the same supplementary channel the hard springs which occa- sionally occur would be diverted off and prevented from mixing with the soft water of the selected springs.The supplementary channel would require to be of sufKcient capacity to provide also for the escape of floods as well as the ordinary surface drainage. The extreme difficulty of keeping the two streams apart as both must have openings everywhere to receive their respective supplies is obvious and appeared to us insuperable. It appears then that the original plan of obtaining a great supply from the springs apart from the streams cannot fail to be defeated by the difficulties of collecting. The water of the streams would require to be used as appears to be intended in the modified I‘ scheme of the Metropolitan Sanitary Water Company,” which would alter considerably the character of the project.The coolness and purity of the springs would necessarily be sacrificed in part. The streams obtain at some places water which has been used in irrigation and also the drainage of cultivated land. Being also soft in quality they acquire a taint of vegetable matter with extreme facility of which we saw instances in the ponds. The streams would of course also be subject to turbidity from floods. Their -100 CHEMICAL REPORT ON THE hardness increases as they descend from field drainage and also from hard springs of which that at the Moors Cosford may be taken as an example amounting to 10O.8 although indistinguishable in its source from a soft water spring.Dr. R. Angus Smith ascer-tained the hardness of three ponds in this district to be Frensham Pond ......5.45 degrees Little ditto .......8-50 Abbott’s Pond ......5-25 The stream to the mill-dam at Sickle paper-mill R~Sobserved by us to be of 3.8 degrees of hardness; this is quite within the district. The Bramshot river which drains two-thirds of the Hindhead district leaves it at Frensham bridge with a hardness of 5.4 degrees the whole of which was permanent on boiling. It appeared to us that the general supply afforded from this district would not probably fall below 4 or 5 degrees of permanent hardness if taken from the streams which we believe to be unavoidable. This conclusion is not opposed by the recent observations of Mr.Bateman who reports to the Metropolitan Sanitary Company respecting the Surrey gathering grounds in the followiq terms :-‘< I have not been able to discover the fall quantity of water of one degree of hardness promised by the Hon. MI*. Napier in his reports to the Board of Health; but I have no hesitation in expressing my belief that a supply of at least 50 millions of gallons per day of very excellent water under 5 degrees of hardness in dry weather and less in wet may be conveniently obtained by simple means of collection.” 4. -THE QUESTION WHETHER ANY COMPARATIVE INCONVENIENCE WOULD ARISE FROM A SUPPLY OF SOFT WATER TO TEIE METROPOLIS WITH THE PRESENT SYSTEM OF DISTRIBUTION. The chief points to be cornsidered as unfavourable to the appli- cation of soft water for the supply of a town in the peculiar con-ditions of the metropolis appear to be the following.The anti-putrescent quality of the present hard supply would be lost and the water rendered less fit for the few days’ storage which must always be had in reserve to meet the casualties of city distribution. Increased attention would therefore be necessary to insure the absence of decomposable organic matter from the water selected as the soft supply and to protect it against subsequent organic contamination ;but such difficulties are already overcome in the supply of many smaller towns and no doubt would be success-fully met as occasion arose on a larger scale. A greater discolouration of the water from oxidation of the iroii pipes might also be apprehended than is observed with the present SUPPLY OF WATER TO THE METROPOLIS.401 hard and alkaline supply particularly if the water were allowed to stagnate in them. But it is the solvent action of soft water on lead which is calculated to excite most alarm with the general use of house-cisterns and the uuiversal use of service-pipes of that metal under the present system of distribution. Of the soft spring waters from Surrey the corrosive action on lead is remarkably small according to our own observa- tions which generally accord with the conclusions of Mr. Napier on that point with the striking exception of the water from the Yunch- bowl Hindhead of which the power to dissolve lead proved to be rather considerable.The inactivity of the other samples we would refer more to the smallness of the quantity of dissolved oxygen which they con- tain than to the absence of carbonic acid the cause suggested by BIr. Napier. But there is little hope of a suflicient supply being ob- tained from these springs of this extreme degree of softness; and the harder supply from the streams of the same district would probably not differ much from the supply of Glasgow and some other large towns where the water is always exposed to lead service- pipes and also occasionally kept in lcaden cisterns although the general supply is constant without any apprehension of lead poi- soning . River watcr or spring water from the chalk strata softened arti- ficially to about 3 degrees of hardness a-as proved by our own obser- vations to have no dangerous action upon lead.The experimental results obtained in a long inquiry under-taken to illustrate the action of water in various circumstances upon lead are not adapted for statement in this Report. The subject is one of great difficulty and is still far from being exhausted. The most important practical conclusions which we have arrived at are the following Certain salts particularly sulphates to which a protecting effect is usually ascribed did not appear to exercise uniformly that useful property. Some salts on the other hand such as chlorides and more particularly nitrates may increase the solvent action of water. Of all protecting actions that of carbonate of lime dissolved in car- bonic acid appeared to be the niost considerable and surest.The most practical perhaps of our observations is the extraordinary influence remarked of the small quantity of carbonic acid which water usually contains upon the results. This effect is fortunately to neu- tralize to an extraordinary degree the usual solvent action on lead which water exercises through the agency of the oxygen dissolved in it. The soluble oxide of lead is converted into the carbonate which although not absolutely insoluble appears to be the least soluble of all the salts of lead. Pure water did not dissolve a quantity of carbonate of lead greater than one-sixtieth of a grain to the gallon or one part of lead in four CHEMICAL REPORT ON THE millions of water; while water on the other hand which contained already so much as six grains of oxide of lead dissolved in it to the gallon had the quantity of metal reduced to one fifty-seventh of a grain by free exposure to the atmosphere for twenty-four hours; the lead being deposited as carbonate of lead in consequence of the absorption of carbonic acid gas.So minute a trace of lead remaining in the water could have no possible influence on health. The quantities just stated also represent pretty closely the proportion of lead which was dissolved by water left in contact with the metal in a divided state during a period of not more than twenty-four hours in two experiments; the water being simply distilled water in one experiment and dis- tilled water containing 3 per cent of its volume of carbonic acid gas in the other.The pure water became highly poisonous but that containing carbonic acid remained safe. The lead was in the form of the lead pyrophorus prepared from the tartrate of lead in which the metal is in an extreme state of division and therefore exposes an enormous surface to the water. Carbonic acid is usually present in well river and lake waters in the quantity sufficient for protection; and the immunity of such waters from lead impregnation we would ascribe often more to their carbonic acid than to the salts which they may also contain;. for lead placed in distilled water which has been boiled to expel its carbonic acid is no longer sufficiently protected by the addition of the same salts.It is true however that a certain excess of carbonic acid in waters such however as is very unusual may give solubility to the carbonate of lead; but this solubility is not to be compared to that of carbonate of lime the carbonate of lead requiring for solution a proportionally much larger quantity of gas. Organic matter in a soft water is doubly dangerous as the rapid corrosion which it occasions may be followed by solution of the lead- salt formed when the carbonic acid is either deficient as in rain water generally or present above the safe proportion. The properties of water which enable it to act at times with un- usual vigour upon lead are little understood and seem often to arise from the accidental action of local and very limited causes such as the presence of decaying leaves and impurities which may only affect a small volume of water.These causes are of a kind most to be dreaded in the supply of a single residence in which the whole volume of water might at a time assume the same dangerous com- position. But such causes probably often counteract each other when large volumes of water are mixed together as in the supply for a town. It is at least difficult to account otherwise for the fact that no recent and authenticated case can be cited of the health of any of the numerous towns lately supplied with soft water being affected by the use of leaden distributory tubes although apprehensions were often entertained from the introduction of soft water as at Boston SUPPLY OF WATER TO THE METROPOLIS.iu the United States ;\-here the subject has excited much attention; and at New York since the introduction of the Croton River. Aberdeen is supplied by water from the Dee under 14 degrees of hardness which is distributed by iron mains and taken into the houses by leaden service-pipes to which leaden cisterns generally of small dimensions are commonly attached. The supply is constant and amounts to about one million gallons a day. A very careful and valuable series of experiments were lately made by Dr. John Smith Fordyce Lecturer in the University with the view of ascertain-ing the action of the water on the leaden pipes by which it is conveyed. These pipes vary from 12 to 100 yards in length. In some instances no indication of the presence of lead in the water which had passed through the pipes was found; in others however small quantities of lead were discovered in solution.The quantities varied from one-bundredth of a grain to about one-twentieth of a grain of lead in a gallon of water. Dr. Smith concludes that less than one-twentieth of a grain of lead in the gillon of water produces no deleterious effect upon the health of those using the water for dietetical purposes and that the lower limit of the deleterious action is between one-tenth and one-twea tieth of a grain of lead to the gallon of water. Here then is a po-pulation it might be supposed constantly on the verge of danger from lead poison but in reply to our inquiries upon the subject we are assured by Dr.Dyce the eminent physician of Aberdeen that during a period of seventeen years he has never known an instance of illness from this cause. He adds in his letter “1 have mentioned the circumstance to several of my colleagues and they all decidedly say that such a complaint is wholly unknown to them.” From Whitehaven also where water of the same extreme softness has been in use for the last six months we learn that no case of lead poisoning had been seen or beard of by the medical practitioners of the town which could be attributed to the use of the water. No cisterns however are used there nor in any of the other towns where soft water has lately been introduced as they may be dispensed with on the system of constant supply which appears always to have been adopted with the soft water.We are disposed therefore to conclude that the danger from lead in town supplies of water has been over-rated; and that with a supply from the Water Companies not less frequent than daily no danger is to be apprehended from the use of the present distributory apparatus with any supply of moderately soft water which the rne- tropolis is likely to obtain. (HEMIGAL REPORT ON THE 5.-OF THE WATER PROPOSED TO BE SUPPLIED FROM WATFORD. The water which it is proposed to bring from the neighbourhood of Til’atford for the supply of the metropolis clairiis consideration as being entirely spring-water and has a peculiar scientific interest as representing the pure primitive basis of the river water which is at present consurned.A supply of water of the same description is also offered from the south side of the river to be derived from the chalk strata upon the line of the South-Eastern Railway and the quantity attainable on either side is said to be PO considerable as to exceed the actual requirements of the metropolis. Of the chalk district which surrounds London on all sides and covers an area of not less than 3000 square miles the upper strata appear to be charged with water to a height of several hundred feet above the level of the sea. This water issues again in numerous natural springs or may be reacbed by moderate boring. The daily yield of single springs or of artificial wells in some parts of this district is remarkabie for its quantity often amounting to 300,000 gallons and occasionally rising to 1,000,000 gallons and upwards ;a copious- ness of flow which is referred to the chalk rock being highly per- vious to water from its fractured and cavernous state.This chalk spring-mater is not to be confounded with the water of the deep wells of London although the latter are carried into the chalk strata below the clay but differs as completely in composition froin the latter as any two waters can well do. Nor does any evidence exist of a relation or dependence of the London deep wells upon the water of the Chalk districts ; nor reason to infer that the yield of the latter would be restricted within the narrow limits of the former. Indeed all grounds for comparison of the two waters will disappear if it is true as inany well-informed persons believe that the deep wells of London draw their supplies chiefly froin the sands under the blue clay and above the chalk the water of which sands appears to flood the upper beds of the chalk.The superposition of the thick mass of strata which form the London clay certainly alters con-siderably the condition of the chalk below it and renders it no longer comparable with the water-bearing strata of chalk in Hert- fordshire and Kent which are not so covered and are situated above the level of the sea. The whole original supply of the New Biver Company from the Chadmll and Amwell springs was water of the kind under consideration and a very sensible proportion of the present large supply of that company is still spring or well water of the same nature.The proposals of the ‘‘Loiidon (Watforcl) Spring Water Company” extend only to a daily supply of about 8,000,000 gallons. But the SUPPLY OF WATER TO THE METROPOLIS. 405 area of land sloping towards Watford and consisting for the niost part of chalk hills embraces more than 1200 square miles aid is estimated by Mr. Homersham the Engineer of the Company as equal to a daily supply of 408,000,000 gallons; the quantity of water which reaches the lower fissures of the chalk being calculated at one-half of the rain-fall. A well sunk in Bushey Meadows in 1840 when this source of supply was first recommended by Mr. R. Stephenson has been found capable of yielding by pumping 1,800,000 01' ncarly two million gallons per day.This well is 12 feet 6 inches in diameter at the bottom and 34 feet deep with 4 small bore-holes 5 inches in diameter descending 130 feet below the surface of the ground. The surface of the water in this well when lowered to its greatest depth by pumping is said still to stand 136 feet above Trinity high-water mark. It is proposed to obtain the remaining portion of the water required by this Company by sinking other wells in Bushey Meadows or by driving adits through the chalk formation under the meadows. The site of the experimental well referred to is on the banks of the Colne within three-quarters of a mile of the town of Watford and distant in a north-westerly direction about fourteen miles from Cumberland Gate Hyde Park.The water of this well was not in a suitable state for examination when visited in February last owing to the access of surface water. The supply of water for examination was therefore taken from other wells in this district namely in the town of Watford at Batchworth near Watford and at Redbourn near St. Alban's. Although the extreme distance of these sources from each other is more than eight miles the results of their analysis are quite similar and also corrcspond closely with anterior analyses of the well in Bushey Meadows. 1. ANALYSIS OF CHALK SPRING WATERS FROM WATFORD. Ba;;%h Redboitrn 1 Water. Grains in the Imperial Gallon Lime . . ... 9.0330 10.3792 Magnesia. Potassium . . ... ... 0,3587 0.4746 0.2580 0.3400 Sodiiim ..... 0.8246 0.3340 Sulphuric acid. Chlorine. . ... ... 0.9471 0.6142 0.3778 0.6360 Carbonic acid . Silica . . ,.. ... 15.0220 1.5900 14-1 640 1.1600 Nitric acid . ... 0.1540 0*7000 CHEMICAL REPORT ON THE 2. ANALYSIS OF CHALK SPRING WATERS PROX WATFORD. Batchworth Redbourn Water. Water. Carbonate of lime ...... 16.13 17-94 Sulphate of lime ...... 0.11 Nitrate of lime ...... OIh3 1.06 Carbonate of magnesia ..... 0.75 0.53 Chloride of sodium ..... 1-01 0.85 Sulphate of soda . ..... 131 19 Chloride of potassium ..... 0.25 99 Sulphate of potassa ..... 0 44 0-58 Carbonate of potassa ..... 0.48 Silica ........ 1.59 1:; 6 Organic matter ...... 1.26 93 Total ....... 23.20 22.48 Residue obtained on evaporation ...22-97 2 1.63 Free carbonic acid in cubic inches at 44O F. . 15.3 12.48 Free carbonic acid grains in the gallon . . 7.6 6.24 Suspended matter ...... Hardness observed ..... 18G 17b On comparing the Watford spring water with the New River water and Thames water as supplied by the Water Companies a considerable similarity is observed in the character of their saline constituents. The lime is in larger quantity in the spring water but then it is nearly if not entirely in the state of carbonate. The earthy sulphates which give rise to permanent hardness are almost entirely absent from the spring water. The general character of this supply may be farther described as follows :-1. The spring water contains no matter in suspension to cause tur- bidity or colour ;its clearness and brilliancy are unexceptionable.2. It possesses a desirable coolness having at all seasons a tempera- ture between 50' and 52'. 3. The amount of organic matter it contains is inconsiderable and of a kind which appears to be incapable of undergoing piitrefactive decomposition so that it may be safely disregarded. 4. The salts which it contains would not interfere with its use as a beverage. It is indeed a choice water for drinking. 5. The great and obvious objection to the chalk spring water is its hardness which when the water is first drawn is uniformly very nearly 18degrees or 4degrees harder than the present metropolitan supply. The weight to be assigned to this objection however appears to be much reduced by the following considerations.A portion of the carbonate of lime which occasions the hardness is deposited from this water when exposed to the atmosphere with SUPPLY OF WATER TO THE METROPOLIS. remarkable facility from the escape of carbonic acid gas. According to the statement of Mr. Homersham which we have no reason to doubt this water when collected and allowed to remain for a few days in reser- voirs suitable for distribution becomes as soft or softer than Thames water. The Redbourn water was observed by us to soften by exposure to air for forty-eight hours in a shallow vessel without any sensible evaporation from 17’08 to 14O a visible crystalline deposit of carbonate of lime appearing at the same time.This softening may go on to a greater extent than is generally supposed for in an extreme case where the Redbourn water was exposed to air in a shallow glass basin for eight days and one-fifth part of the whole water was lost by evapora- tion the remaining four-fifths exhibited a reduced hardness of only 9.1 degrees. Ill the course of an investigation of the spontaneous softening of chalk waters by exposure a subject which appeared to us of some importance it was discovered that these waters may be softened in a few minutes by means of agitation in air to about 13.5 degrees provided a quantity of the precipitated carbonate of lime be previously mixed with the water. The crystalline grains of chalk appear to promote the separation of carbonate of lime from the water; the grains no doubt increasing in size by an accession of matter.Siliceous sand agitated in contact with the hard water did not produce the same effect. The chalk spring-water is softened very fully as might be expected by boiling. The Batchworth water merely heated to the point of ebullition fell to 12 degrees of hardness j by five minutes’ boiling to 5.6 degrees ; by fifteen minutes to 4 degrees ; by thirty minutes to 2.8 degrees and by an hour’s boiling to 2.6 degrees. The final result almost coincides with the effect of boiling upon a solution of pure carbonate of lime in distilled water containing carbonic acid gas which was reduced to 2.4 degrees. New River water it will be remembered has its softening limit by boiling at 4.1 degrees and Thames water at 5.5 degrees.In all applications of water therefore where it is boiled no loss but on the contrary a small gain would be experienced by substituting the chalk spring-water of Hertfordshire for the present supply. The high degree of hardness of the chalk spring waters is also greatly redeemed by their peculiar adaptation to the softening pro- cess. The Batchworth spring was thus reduced to 2-6degrees of hardness when lime-water was used and to 2.8degrees by means of the solid hydrate of lime; the Redbourn spring to 2.5 and 2.6 degrees. Such is the degree of softness therefore at which this supply is attainable. From the extreme purity of the water the Precipitated chalk falls entirely colourless and indeed from its finely levigated condition might be sold as whitening.The precipitation appeared to be completed within twelve hours and was so perfect that no filtration of the water was necessary. The water retained all its CHEMICAL KEt’OR?’ ON THE original brightness arid transparency and acquired no flavour or other property by which it could he distinguished from the equally soft waters supplied by nature. The experience obtained by us of this softened water as a beverage for some weeks was confirmatory of the statements that the palate becomes gradually reconciled to the impression of a soft and pure water. It is a valuable property of the chalk spring-water that in practice it may be softened fully or partially with the same facility or to any degree desired ; the precipitate falling quickly and completely in every case and leaving the supernatant water clear and colourless.Respecting the supply of chalk spring-water from the south side of the Thames our information is principally derived from a Report by Mr. Peter W. Barlow on the supply of water to be obtained from the North Kent district addressed to the Chairman and Directors of the South-Eastern Railway Company to which is added a Geolo- gical Report on the district by Professor Ansted with analyses of the waters by Professor l3rande.g The district directly available extends about 20 miles along the North Kent Railway between Blackheath and Higham and includes according to Mr. Ansted about 180 square miles of country consisting of chalk beds of great thickness re-posing upon the Wealden clay which is very retentive of water.The chalk is said to be of a somewhat open texture the surface broken by numerous fissures and the mass of the rock to have many joints and also faults. Mr. Ansted found by experiment that chalk in this state and when fully saturated contains about two gallons of water in each cubic foot of chalk. That the district is composed of highly pervious strata appears from the fact remarked by Mr. Barlow that the whole rain which falls upon it does not produce any surface stream but appears to escape chiefly by subterraneous channels into the Thames. The water issues again at some points in great abundance. One group of springs which occurs near Northfleet Station were found by Mr.Barlow to discharge from 7 to 9 million gallons a-day; and the whole supply which may be conveniently intercepted by adits or numerous bores into the chalk along the line of the railway is roughly estimated by Mr. Ansted at 60 million gallons daily and the supply at a moderate depth considered to be practically inex- haustible. It does not fall within our province to discuss engineering estimates for works or even calculations of quantity but the interest of the information and its trustworthiness as coming from BIr. Bar- low excuse a reference to the outlay involved in a scheme of so much novelty. The estimate for bringing the water to the terminus at the Bricklayers’ Arms for the supply of London on the south side of the Thames is 8150,000 which includes the cost of a heading or small tunnel driven under the line of railway at or about the level of low-water mark with borings every half mile; and no liability * Printed by James Truscott Nelson Square London 1850.SUPPLY OF WATER TO THE METROPOLIS. whatever is incurred to compensate land-owners for existing rights to water. The good quality as well as the abundance of the water from the chalk has been proved in every case according to Mr. Barlow where the water has been required by the Railway Company and seven of their locomotive stations are thus supplied. The water of the southern chalk districts is also found suitable for town use as at Gravesend Folkestone Dover Brighton Lewes Portsmouth Rams- gate Deal Canterbury Arundel and Winchester.The town-supply of Gravesend was taken for analysis to illnstrate the chemical qualities of the chalk spring-water of Kent. The sample was perfectly bright and colourless and proved to be very similar in composition to the Hertfordshire waters. 1. ANALYSIS OF TVATER FROM GRAVESEND WATER-WORKS. Grains in an imperial Gallon Lime ........ 10.5630 Magnesia ....... 0.1334 Potassium ....... 0.5900 Sodium ....... 0.9040 Iron alumina and phosphates ... 0.2557 Sulphuric acid(S0,) ..... 0,5925 Chlorine ....... 1.1775 Carbonic acid ......14.7900 Silica ........ 1.0150 2. ANALYSIS OF WATER FROM GRAVESEND WATER-WORKS. Grains in an Imperial Gallon. Carbonate of lime ...* . 18.86 Sulphate of lime ......99 Carbonate of magnesia .... 0-28 Chloride of sodium ..... 1.94 Sulphate of soda ....* . 0.74 Sulphate of potassa ..... 0.38 Silicate of potassa ..... 0.65 Silica ........ 0.69 Iron alumina and phosphates .* . 0.26 Organic matter ...... 0.73 _._. 24.53 Residue obtained on evaporation ... 24.54 Free carbonic acid in cubic inches ... 13.31 Free carbonic acid grains in the gallon .. 6.5 Suspendedmatter ...... Hardness ....... 19):56 The hardness of this water was reduced by boiling from 19.5 degrees to 3.2 degrees The water from a newly-opened well in the chalk at the Railway Station Gravesend fell by boiling from CHEMICAL REPORT ON THE 21.3 to 2-8 degrees. These waters admit also of an equally high degree of softening by the lime-process as thc Hertfordshire chalk springs to which they appear to be in every respect similar and equivalent in value.6.-OF THE PROPERTIES TO BE PREFERRED IN THE WATER SELECTED FOR THE SUPPLY OF THE METROPOLIS. "he properties which we would esteem of most value in water to be supplied to the metropolis are 1. Freedom from putrescible organic matter. 2. Freedom from constant or even occasional discolouration by day and vegetable matter with perfect brightness and clearness. 3. Softness. 4. Coolness. The nearer the sources of rivers are approached the more fully are they likely to possess the two first requirements freedom from organic impregnations and from colour. The New ftiver water may be instanced as offering the most favourable exhibition of the good qualities possessed by any portion of the present metropolitan supply.Taken from the Lea above Ware this water has a superiority which is generally admitted over the supplies from the Thames which would no doubt be further increased by the removal of the Hertford drainage by recourse for additional water to the higher tributaries of the Lea as proposed by the River Lea Trustees and by shortening the channel of the New River by about twelve miles which is also contemplated. But it is only by proceeding to the actual sources of rivers that the water of the latter can be protected completely from field and house drainage. Hence the general disposition to abandon rivers as sources of town supply and to allow them to remain as they must always be the natural and indispensable channels of drain-age and the occasional means of fertilizing irrigation.The contemplated improvements of the New River appear to embody a portion of the comprehensive scheme of Captain Vetch who after a careful survey undertaken by direction of the late Metropolitan Board of Sewers recommended the appropriation of the unobjectionable chalk streams on either side of the Thames as the future sources of supply; abandoning the River itself for its purer tributaries and giving a preference to those streams which enter the Thames below London so as to retain the volume and scouring power and with these the salubrity of the upper part of the river unim- paired.To this last object Captain Vetch attached great importance with reference to the prospective increase of the nietropolis which he reminds us has doubled its population within forty years. The eminent engineer Mr. Telford to whom the question of the metro- SUPPLY OF WATER TO THE METROPOLIS. 41 1 politan supply was referred by Government after the Water Inquiry and Report in 1828 had previously recommended after a prolonged investigation to bring the water from the River Verulam near Watford for the supply of the districts on the north side of the Thames and from the River Wandle for the supply of the dis- tricts on the south side. In 1810 a further step ~7astaken in the same direction the "London and TVestminster Water Works Company" being at that time established for supplying the metropolis with water from the springs in the chalk near Watford.This Company proceeded upon a Report by Rfr. ltobert Stephenson which appears to be founded on sound scientific principles and great local knowledge. Mr. Stephenson concludes that the necessary supply for London could be obtained and coiivcyed from that source and speaks in the highest terms of its quality. He expresses his surprise that with thc exception of the abortive project to obtain water by perforating the London clay all preceding proposals "in-cluding Mr. Telford's should have contemplated using the water of streams which are all subject to be affected by the surface-drainage of a more or less extensive tract of country and consequently only a very few degrees better than that already in use." Our great engineers have thus returned step by step to the original idea of Sir Hugh Rliddleton who had recourse to the pure fountain-heads of Hertfordshire for the supply first brought by him to London by the New River; acting no doubt upon the traditions of antiquity and the example of the Roman hydraulic works which are still unrivalled.Of the two divisions of Hertfordshire which are drained respectively by the Colne and the Lea the former or north- western district containing Watford appears to exceed in available water sources the latter or north-eastern district the field which is already occupied by the New River Company. The inhabitants of London appear to have within their reach in these chalk strata a supply of water which is asserted on good authority to be inexhaustible and which may be considered as every- where of an uniform composition and quality The rain falling upon the downs and elevated ridges is rapidly absorbed by the soil and enters the chalk beds through the porous arid amply aerated channels of which it circulates much of it probably for centuries before subsiding to the lower level of the valley springs.Hence a full decomposition of any alterable organic matter and the assumption by the water of a constant and uniform character. The chalk spring-water unites the greater number of the desirable qualities already enumerated. It contains absolutely nothing of organic origin capable of further alteration or decomposition and is therefore wholly unobjectionable on the ground of organic constituents.Its clearness and brilliancy also appear perfect from the cornplete absence of suspended matter and are highly attractive. Possessing VOL. IV.-NO. xvr. FF CSEMICAL REPORT ON THE at all seasons the mean temperature of the year the same water has an agreeable coolness and freshness which might certainly be preserved in a great degree by proper means of conveyance and distribution. The only other quality desired in a town supply was softness. The chalk spring-water is not naturally a soft water. In this respect it is inferior to the present supply being one-fourth harder; but it will be remembered that the hardness of both is principally of the temporary kind and that after boiling the advantage is with the spring water.It is however in the facility and completeness of the removal of this hardness that the superiority of the spring over the river water is most apparent. The softening operation by the use of lime is applicable in all seasons to the spring water which indeed adapts itself with singular felicity to that process the carbonate of lime always precipitating with rapidity and so completely as not to create a necessity for filtration. The chalk spring waters can thus be commanded with certainty under three degrees of hardness which is probably the extreme limit attainable anywhere in England for a great supply. The lower price of lime in the chalk districts and the reduction in the labour of mixing must also bring the cost of the process considerably within the estimate formed at the Chelsea Works and would not we believe form a greater addition than a sum equal to two per cent upon the present price of water.This is without allowing anything to be obtained in return for the precipitated chalk which would certainly have some market value. The chalk spring-water after being softened is an extremely pure water. It appears to be considerably superior even to the soft water from the streams of the Surrey Sands. The chalk water alone is uniform in its excellence at all times the sources of it lying beyond the influence of weather or season In the judgment of the Com-missioners this softened chalk water is entitled from its chemical quality to a preference over all others for the future supply of the Metropolis.It is no longer possible to disregard the chemical means of remov-ing hardness or to represent them as impracticable on a great scale; they place the question of water-supply upon an entirely new footing. Efficient as these means already are we confidently look to their farther improvement when the large results of practice come under the eye of the engineer and scientific observer. Another mode of partial softening without the consumption of lime or any other material by the united action of air and granular carbonate of lime upon the carbonated water has been already referred to which may probably soon have its powers tested either as an auxiliary to Dr.Clark’s process or as a substitute for that process when a less considerable softening is required. An incidental advantage of artificial softening for the London SUPPLY OF WATER TO THE METROPOLIS. supply is that the change in quality can be graduated to any point desired. It may be advisable to furnish the water at first with a hardness of 5 or 6 degrees which is considerably above the point at which any action upon lead need be apprehended and therefore compatible with the cistern- storage of water which the actual system of supply requires. The circumstance that this residuary hardness after liming yields readily to boiling combined with the absence from the spring water of all colouring impurity would insure that water a decided preference for washing and most other applica- tions even were it no further softened.But it might be reduced we believe with perfect safety to 3 degrees of hardness as soon as the taste and habits of the cousumers were aceoniniodated to so soft a water. To obtain the full advantage of its great coolness in the hot suninier months the supply would require to be constant and the house- pipe to communicate directly with the main. But although this change is desirable on other important grounds it is not indispen- sable to the first introduction of the softened chalk sprin,- water. 0. The water recommended appears to approach most closely to the standard of all that is excellent in a town supply and is worthy of the greatest efforts and grandest works to procure and convey it.But the sources are near at hand and the water is attainable without difficulty or great expense. With such a noble appli-cation of the chalk spring-water in view as the supply of the metropolis it would be a desecration to permit that water to be wasted on other uses and most impolitic to allow the possession of it to pass into private hands. It is our deliberate opinion which we would enforce in the strongest terms that the much desired and most necessary improvement in quality of the London water is associated with these sources of supply and will depend upon their proper application to the uses of the Public. We have the honour to be Sir Your very obedient Servants THOMAS GRAHAM. W. A. MILLER. A. W.HOFMANN London June 17,1851. To the Right Hon. Sir GEORGE GREY Bart. Her Majesty’s principal Secretary of State for the Home Department. FF 2