Part 16

This water was selected as exemplifying the general composition of the shallow well-water of the City of London, when the well is situated near to a burial-ground, as is frequently the case with the parochial wells.

The water from this well is perfectly bright, clear, and even brilliant; it has an agreeable soft taste, and is much esteemed by the inhabitants of the parish, although, as will be seen by the subjoined analysis, it is an exceedingly hard water, and the large quantity of earthy salts it contains renders it unfit for all culinary and for most domestic purposes.

When heated to the boiling point, this water becomes turbid, and by continued boiling of an imperial gallon of the water for two hours, 23·03 grs. of solid matter were deposited, consisting of 22·15 grs. carbonate of lime, and 0·88 carbonate of magnesia, with a trace of phosphate of lime.

An imperial gallon of this water, when evaporated to dryness and the residue dried at a temperature of about 300° Fahr., left a residue which amounted to 88·07 grs. From another sample of the same water taken a month afterwards, 84·53 grs. of solid residue were obtained.

By an analysis, an imperial gallon of the water gave--

Carbonate of lime 28·97 Carbonate of magnesia 2·61 Sulphate of lime 17·85 Chloride of sodium 16·95 Nitrate of potass 12·40 Nitrate of soda 1·50 Nitrate of magnesia 4·92 Nitrate of ammonia 4·01 Silica 0·80 Phosphate of lime traces Organic matter ------ 90·01

The residue left by evaporation was of a light brown colour; when calcined at a low red heat it became slightly charred; but I could not, with any degree of certainty, determine the precise quantity of organic matter it contained: it was certainly very small.

The excess of solid matter, as shown by the analysis, over the quantity obtained by evaporating the water to dryness, is owing to the decomposition of the nitrate of ammonia.

The quantity of alkaline and earthy nitrates in this water is very remarkable. These salts are doubtless derived from the decomposition of animal matter in the adjacent churchyard. Their presence, conjoined with the inconsiderable quantity of organic matter which the water contains, illustrates in a very forcible manner the power the earth possesses of depriving the water that percolates it of any animal matter it may hold in solution; and moreover shows in how complete and rapid a manner this process is effected.

In this case the distance of the well from the churchyard is little more than the breadth of the footpath, and yet this short extent of intervening ground has, by virtue of the oxidizing power of the earth, been sufficient wholly to decompose and render inoffensive the liquid animal matter that has oozed from the putrefying corpses in the churchyard.

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The result of these analyses confirms the general statement that the water derived from the sandy districts of Farnham and Bagshot is of eminent purity, and therefore peculiarly fitted for all those purposes of domestic and manufacturing economy which require the use of a very soft water.

When regarded in conjunction with the analyses made by other chemists, of the water taken from the streams, pools, and other collections of water in the same locality, it also points out that, if it be desirable to secure the water in its utmost state of purity, it should be collected at its very source, before it has had time to become impregnated with the various mineral and saline ingredients of the different soils through which it would have to pass. The total absence of free carbonic acid in these waters is a very remarkable fact, and one which I believe has not been hitherto noticed.

It will also be perceived that the principal solid constituent of the water supplied by the New River and the East London companies is carbonate of lime, held in solution by an excess of carbonic acid, an opinion already expressed by several chemists. These waters also contain an appreciable quantity of oxide of iron.

When the water from these sources is boiled, or simply brought to the boiling temperature, the excess of carbonic acid is driven off, and the carbonate of lime being thus deprived of its solvent, the greater portion of it, together with the oxide of iron, is thrown down in the form of an insoluble crystalline powder, while the water is rendered comparatively soft and pure.

Were it therefore possible that means could be devised by which the quantity of water necessary for the daily supply of London could be deprived of its excess of earthy carbonates in a manner sufficiently economic, comprehensive, and effectual, the citizens of the metropolis would enjoy the advantage of a tolerably pure soft water, free from those inconveniences which attend the use of the present hard-water supply.

Confining myself wholly to a chemical view of the subject, the principal disadvantages attending the use of hard river waters are--

First, The precipitation of earthy matter on the inside of vessels in which the water is heated. This furring of the vessel, as it is called, leads to its more rapid destruction, and has also the inconvenience of rendering it more difficult to cleanse, so that the flavour and odour of the various substances cooked in it are not readily removed. From the non-conducting power of the earthy crust, an increased consumption of fuel is also required for the due heating of the vessel.

Secondly, The admixture of the earthy salts with the various articles of food submitted to the action of hot water.

Thirdly, Diminished solvent power, as required for the purposes of the chemist, the brewer, and for many domestic purposes, as in the making of tea, soups, &c.

Fourthly, Diminished cleansing power, both as regards the direct solvent action of the water, and also as causing the decomposition of soap, and consequent increased consumption of that article. I must, however, remark that the annual loss reported to arise from this cause appears to me considerably overrated, since water is rarely used for the washing of linen until previously boiled, and the common practice of adding carbonate of soda to the water completely destroys the ill effects resulting from the hardness of the water. The additional expense of the carbonate of soda, thus added, is too trifling to merit notice; but when this salt is used in excess, as is generally the case, it produces the more serious evil of materially impairing the strength of the fabric submitted to its action.

The only real advantage which hard water possesses over soft (and in the present state of things one of considerable importance), is, that it does not act upon or erode the lead of the pipes and cisterns in which it is contained.

There are also some particular cases of minor importance in which hard water is preferred; thus dyers prefer hard water for rinsing of their goods, soft water extracting too much of the colour; but these cases are comparatively rare, and might be easily accomplished by an artificial hardening of the water.

The following Table indicates the relative hardness of the different waters as determined by the Soap test; distilled water being taken as unity, as proposed by Professor Brande. It also shows the effect of boiling in reducing the hardness of the water. The numbers express the direct quantity of an alcoholic solution of soap, which an equal bulk of each water requires in order to form a lather remaining permanent for from five to ten minutes.

Distilled water 1·0 Water from Haslemere 2·4 Boorley 1·5 Barford 2·4 Water of the New River Company 13·3 Ditto after being boiled 4·7 Water of the East London Company 19·0 Ditto after being boiled 5·6 Water from the well in Bishopsgate-street 47·4 Ditto after being boiled 26·0

The experiments which I have recently made on the action of pure water upon lead, clearly point out the necessity of keeping the pipes always full, especially in those instances in which the water has a tendency, however slight, to erode the lead. As the importance of this part of the question does not appear to have been sufficiently appreciated by the advocates of a constant instead of an intermittent supply, I will briefly recount the facts of the case, although I do not offer them as presenting anything particularly novel. If a piece of bright lead be placed in a stoppered bottle, completely filled with recently distilled water, so that the access of air be wholly excluded, the lead is but very slightly acted upon, and it is only after the lapse of three or four days that its surface becomes spangled with a few minute crystals of carbonate of lead.

If the stopper of the bottle be now removed, the lead still remaining beneath the surface of the water, the erosive action of the water on the lead proceeds more rapidly, but still slowly. But if now a portion of the water be poured off, so as to leave the lead only partially immersed, rapid action on the lead immediately commences. In the course of thirty-six or forty-eight hours, its surface becomes coated with crystalline scales of carbonate of lead, which, falling off, are succeeded by others, so that after the lapse of a few days an abundant deposit of carbonate and hydrated oxide of lead is found at the bottom of the vessel. If the experiment be made with distilled water that has been previously agitated with air, so as to completely aërate it, the lead is more rapidly acted upon, even in a closed vessel, thus clearly showing how much the action of the water upon the lead depends upon the presence or absence of atmospheric air.

Now, in a minor degree, this is precisely what takes place in a leaden pipe conveying water capable of eroding lead. While the pipe is full, comparatively but little action occurs; but when the pipe is filled alternately with air and with water, it is placed under the most favourable circumstances to ensure a rapid erosion of its substance, and consequent contamination of the water.

The rush of water necessarily produced by an intermittent flow must also detach portions of carbonate of lead from the sides of the pipe, even in those cases where the water has no very decided action on lead, and it is therefore far from improbable that in this manner the poison of lead is occasionally conveyed into our kitchens, and becomes mixed with our food.

According to your desire, I have examined the action of the waters from the above-mentioned sources on clean lead, and have arrived at the following conclusions:--the water from Haslemere has a slow though decided action upon the metal, no effect taking place until the lead had been partially immersed for four or five days. After that time, a small deposit of carbonate of lead was perceptible at the bottom of the vessel, although none could be detected in solution. The absence of carbonic acid in the water from Haslemere, Boorley, and Barford, would in all probability prevent their acting upon lead, were atmospheric air at the same time excluded. A piece of lead that had been kept for a week in a closed bottle filled with water from Haslemere did not exhibit the least trace of carbonate of lead, nor could the presence of lead be detected in the water.

It is scarcely necessary to add, that the water as drawn from the pipes of the New River and East London Companies does not exhibit the least solvent action upon lead; when, however, purified by boiling, and placed in contact with lead, crystals of carbonate of lead were observable after the lapse of three days in the water of the New River Company, while, owing to its greater hardness, the water of the East London Company did not exhibit any traces of carbonate of lead until the expiration of more than a week, and even then only in a slight degree. The same waters purified by the patented process of Clark did not exhibit so decided an action upon lead as when purified by boiling; but after evaporating to dryness the water in which lead had been immersed for three weeks, and dissolving the residue in dilute nitric acid, the presence of a minute quantity of lead was rendered evident.

It therefore appears that if leaden pipes, and especially if leaden cisterns, are to be employed in the distribution and storage of water, on the system of interrupted supply, it will be a necessary safeguard, that the water thus conveyed and stored should not be of less hardness than from six to seven degrees, compared with distilled water as unity; and conversely, it also follows, that if the inhabitants of the metropolis are to gain the advantage of using a still purer and softer water, it will be requisite to do away with the existing leaden pipes and cisterns, and to substitute for them some material which shall not communicate any poisonous or noxious ingredient to the water. As matters now stand, we escape daily poisoning by the use of water loaded with earthy salts, and are thus compelled to drink an impure water on account of the impurity of our vessels. Would it not be better, and is it impossible, to drink the pure element from a pure cup?

I remain, dear sir, with much respect, Yours obediently,

THOMAS TAYLOR.

To JOHN SIMON, Esq., F.R.S., Officer of Health to the City of London.

THIRD ANNUAL REPORT.

_November 25th, 1851._

GENTLEMEN,

I have the honour of laying before you, in the various subjoined tables, such information as will enable you to measure the present sanitary condition of the City of London.

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1. The first table (Appendix, No. I.) contains a statement of the present population of the City, as derived from the Registrar-General’s recent census; and it compares the existing numbers in each division of the City with those given at the last enumeration in 1841.

In examining this table you will observe that, during these ten years, the general population of the City has increased about 3⅖ _per cent._; that this increase has not been uniform through the nine sub-districts of your jurisdiction; that in some it has been unimportant; that in others there has been an actual decrease, extending even to 4⅔ _per cent._ on the previous population; while in the whole East London Union the numbers have risen considerably above the aggregate rate of increase, and in the St. Botolph sub-district exceed those of the former census by more than 16 _per cent._

Passing over the minor differences which have taken place in the distribution of the population, I cannot regard that larger increase without apprehension and regret. Probably for the most part it represents the continued influx of a poor population into localities undesirable for residence, and implies that habitations--previously unwholesome by their over-crowdedness--are now still more densely thronged by a squalid and sickly population.

I congratulate your Hon. Court on the recent acquisition of powers (to the nature of which I shall presently advert) for the reduction and prevention of this serious evil.

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2. The second table[61] presents a summary of the City mortality for the year which terminated at Michaelmas last; showing the deaths, as they have occurred, male and female, during each quarter of the year, in the several districts and sub-districts of the City; and including at the foot of each column, a statement of the year’s death-rate _per_ thousand of the living in each such district and sub-district.

[61] _Appendix_, No. V. The calculated death-rates are omitted from this, as from the other annual tables:--the quinquennial rates (App. No. II.) giving more useful results.--J. S., 1854.

You will observe that, during the 52 weeks, dated from September 29th, 1850, to September 27th, 1851, there have died of the population under your charge 2978 persons; giving, for the City aggregately, a rate of nearly 23 deaths for every thousand living persons.

The rate of last year was little over 21 _per_ thousand.

In my last Annual Report I suggested that the death-rate then prevailing was probably (from temporary circumstances) more favourable than the true average of the City; that it corresponded to the period of recovery from severe epidemic influences; that it seemed exceptional; and that you might be prepared for this year’s mortality showing again a tendency to increase.

Such has been the case; and it illustrates the necessity of appealing to cyclical averages for correct intelligence as to the healthiness of a population. To my mind the increased mortality of this year does not indicate any deterioration of the City in respect of sanitary matters under your control; it shows merely that the death-rate, which must be considered our present average for the City, is in truth higher than that which favourable circumstances, foreign to your jurisdiction, last year permitted us to attain.

Looking to the total mortality of the last three years (the period for which I have had the honour of serving your Commission), I find that 9493 deaths have taken place; which, the mean population of the time being 129,922, gives an average rate of 24·35 deaths _per_ thousand _per annum_. This accords very nearly with a death-rate (24·36) deduced from the septennial period 1838-44, during which (according to the Registrar-General) 22,127 deaths occurred in a population estimated at 129,739.[62]

[62] Since 1841, when the Census gave these figures, the limits of the West London Union have been slightly altered. The Inner Temple and Barnard’s Inn have been added to it, while part of St. Sepulchre’s parish has been taken away.

Assuming our City mortality to be accurately represented by these averages, I need not inform your Hon. Court that such a death-rate is unduly high. I have already, in previous Reports, laid before you the materials for measuring its excess,--materials which seem to show that our existing death-rate is nearly the double of that which better circumstances have elsewhere rendered attainable.[63]

[63] The death-rate to which I particularly refer in the text, and which I cited in my last year’s report, is that of a large district in Northumberland, numbering 27,628 inhabitants, where, during the seven years 1838-44, the mortality was at the rate of only 14 _per_ thousand _per annum_; and even in this comparatively low proportion a very distinct share might still be called preventable deaths.

It is not to the City alone of metropolitan districts that this high mortality belongs. Unhappily it affects the entire Metropolis; and we may find other towns in England, and still more on the Continent, where the death-rate is higher than under your jurisdiction. Yet your Hon. Court will not doubt that the standard to be adopted for your estimate of healthiness ought to be the lowest known death-rate; that every avoidable death represents an evil to society; and that, if a mortality of 12, or 13, or 14 _per_ thousand _per annum_ can be reached for one mixed population, there is ample room for discontent among any other population, which finds itself doomed to perish at double the rate of the first.

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3. In the third table[64] all the deaths of the last three years are enumerated in a form which may enable you to compare one year with another, and one sub-district with another, in respect of their several contributions to the total mortality.

[64] This information is now included in the Quinquennial Synopsis, _Appendix_, No. II.

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4. In the fourth table[65] are classified, according to the ages at which they occurred, 9476[66] deaths of the last three years. This table is arranged in a manner to display its results--(1) for each year separately, and (2) for each Union separately, in order that you may observe what local or annual differences have obtained as to the ages of chief mortality. You will notice that in 3469 instances, nearly three-eighths of the whole, death has befallen children under five years old. Children at this age constitute about a tenth part of the population of the City. They accordingly die at about four times the rate which would fall to them as equal participators in the average mortality of the district. The next table will throw some light on this disproportionate excess of infant deaths.

[65] Now embodied in Table VIII.

[66] In the remaining number (17) the particulars of age and residence could not be correctly ascertained.

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5. In it[67] an enumeration is made of such deaths, during the last three years, as have arisen in consequence of acute disease partially or entirely preventable. They amount to 3923--more than two-fifths of the entire mortality of the period.

[67] _Appendix_, No. IX. includes this Table.

I would especially beg the attention of your Hon. Court to the particulars set forth in the successive columns of this table.

The first column shows 391 deaths by fever; and of these, without hesitation, I would speak as entirely preventable. Under favourable sanitary conditions fever is unknown. The deaths arising from it befall for the most part persons in the prime of life, whose premature removal, in the midst of their vigour and usefulness, is not only a direct weakening of society, but is also, in respect of orphanage and widowhood, a frequent source to the public of indirect detriment and expense.

In the second column, swelled by the epidemic visitation of 1849, you will find 902 deaths referred to Asiatic Cholera, and to other kindred diseases. Comparatively few cases of the kind have occurred since Michaelmas, 1849; an overwhelming majority belonged to the summer quarter then terminating, when the Metropolis generally was suffering from the presence of Cholera. I have already had occasion to show you that this frightful pestilence belongs only to localities which, by their general epidemic mortality, have previously been stigmatised as unhealthy; that, over districts otherwise healthy, it migrates without striking a blow; that it may, therefore, with confidence be spoken of as a disease proportionate to removable causes--in other words, as a preventable disease.

I cannot pass over these two columns, without begging you to observe what perhaps may be novel to you. If, instead of reckoning the cholera-deaths as belonging solely to the one year in which they happened, you reckon them as belonging to the whole term of years which elapsed between the two visitations of the epidemic, and distribute them equally over that period, so as to form an average--say for fifteen years, you cannot fail to notice how largely, in the long run, the destruction by fever (which is always here) surpasses the fatality of that Eastern disease; so much so, that the average annual mortality by the latter probably does not amount to half the fatality of the former.