+-------+--------------------+---------+---------+---------+_Reports Relating to the Sanitary Condition of the City of London

| I. | II. | VII. | VIII. | IX. | X. |

| | | | | | |

|of | |Pox, |las, |Fever, |Pneumo- |

| | | | | | |

| | |1849|1850|1849|1850|1849|1850|1849|1850|

+-------+--------------------+----+----+----+----+----+----+----+----+

| 184|Aldersgate Within | ...| ...| ...| 1| 4| 2| 3| 7|

| 572|Aldersgate Without | 1| 5| 4| 3| 14| ...| 27| 12|

| 809|Aldgate | 2| ...| 2| 2| 5| 2| 18| 9|

| 133|Bassishaw | ...| ...| 1| ...| ...| ...| ...| ...|

| 314|Billingsgate | ...| ...| 2| ...| 3| ...| 2| 1|

| 334|Bishopsgate Within | ...| ...| 1| 1| 2| ...| 3| 5|

| *1020|Bishopsgate Without | 4| 5| 3| 5| 10| 3| 41| 19|

| 251|Bread Street | ...| ...| 1| 1| ...| ...| 6| 3|

| 205|Bridge | ...| ...| ...| 1| 2| 1| 3| 1|

| 536|Broad Street | ...| ...| 1| ...| 3| 3| 4| 6|

| 194|Candlewick | ...| ...| ...| ...| ...| ...| ...| ...|

| 499|Castlebaynard | 1| ...| 1| ...| 4| ...| 6| 11|

| 341|Cheap | ...| ...| 2| 1| 2| ...| 5| 3|

| 626|Coleman Street | ...| ...| 2| ...| 3| ...| 10| 9|

| 294|Cordwainer | ...| ...| ...| ...| ...| ...| ...| ...|

| 158|Cornhill | ...| ...| ...| ...| ...| ...| 2| ...|

| 471|Cripplegate Within | ...| ...| 2| 2| 3| ...| 12| 8|

| *962|Cripplegate Without | 3| 7| 3| 3| 17| ...| 33| 29|

| 232|Dowgate | ...| 2| ...| ...| 1| 1| 2| ...|

| 961|Farringdon Within | 1| 1| 1| 1| 4| 1| 15| 17|

| *3533|Farringdon Without | 2| 10| 13| 12| 34| 10| 56| 72|

| 409|Langbourn | 1| ...| ...| 2| 1| 1| 1| 2|

| 166|Lime Street | ...| ...| ...| ...| ...| ...| 1| 1|

| *1258|Portsoken | ...| 2| 2| 1| 9| 1| 14| 10|

| 343|Queenhithe | 2| 1| 1| 1| 7| 2| 5| 4|

| 611|Tower | ...| ...| 1| 3| 1| 2| 3| 8|

| 253|Vintry | ...| ...| ...| ...| 1| ...| 1| ...|

| 235|Walbrook | ...| ...| ...| ...| 2| 2| 4| 3|

| |City of London Union| ...| ...| 1| ...| 2| 1| 3| 3|

+-------+--------------------+----+----+----+----+----+----+----+----+

| 15904|The Deaths from all}| | | | | | | | |

| 480|causes within same }| 17| 33| 44| 40| 135| 32| 285| 243|

|-------|period were 6551 }| | | | | | | | |

| 16384| | 50 | 84 | 167 | 528 |

+-------+--------------------+---------+---------+---------+---------+

+-------+--------------------+---------+---------+

| I. | II. | XI. | XII. |

| | | | |

| | |cough, |_&c._ |

| | |_&c._ |Sept. |

| | | | |

| | |1849|1850|1849|1850|

+-------+--------------------+----+----+----+----+

| 184|Aldersgate Within | 2| 2| 4| 2|

| 572|Aldersgate Without | 13| 9| 16| 19|

| 809|Aldgate | 9| 5| 20| 10|

| 133|Bassishaw | ...| ...| 1| 1|

| 314|Billingsgate | 4| ...| ...| 4|

| 334|Bishopsgate Within | 6| 5| 5| 3|

| *1020|Bishopsgate Without | 32| 15| 35| 31|

| 251|Bread Street | ...| ...| 4| 2|

| 205|Bridge | 2| 1| 1| 2|

| 536|Broad Street | 7| 1| 3| 2|

| 194|Candlewick | 2| ...| 3| 1|

| 499|Castlebaynard | 10| 5| 20| 7|

| 341|Cheap | ...| 2| 5| 3|

| 626|Coleman Street | 6| 2| 12| 7|

| 294|Cordwainer | ...| ...| 3| ...|

| 158|Cornhill | ...| 1| ...| 1|

| 471|Cripplegate Within | 7| 7| 14| 12|

| *962|Cripplegate Without | 31| 15| 19| 21|

| 232|Dowgate | 1| 1| 4| 1|

| 961|Farringdon Within | 9| 2| 11| 10|

| *3533|Farringdon Without | 33| 31| 57| 38|

| 409|Langbourn | 3| 2| 2| 7|

| 166|Lime Street | ...| 2| 2| 1|

| *1258|Portsoken | 12| 10| 9| 18|

| 343|Queenhithe | 4| 4| 1| 6|

| 611|Tower | ...| 1| 4| 7|

| 253|Vintry | 1| ...| 5| 2|

| 235|Walbrook | 1| 1| 5| ...|

| |City of London Union| 1| ...| 3| 1|

+-------+--------------------+----+----+----+----+

| 15904|The Deaths from all}| | | | |

| 480|causes within same }| 196| 124| 264| 219|

|-------|period were 6551 }| | | | |

| 16384| | 320 | 483 |

+-------+--------------------+---------+---------+

Letter by Mr. THOMAS TAYLOR, Lecturer on Chemistry at the Medical

School of the Middlesex Hospital, on the Chemical Qualities of certain

Waters.

4, Vere-street, Oxford-street,

November, 1850.

DEAR SIR,

Having, by your desire, submitted the following samples of water to

chemical analysis, I now beg leave to lay before you the result; and

also, at the same time, to reply to certain questions which you

likewise proposed.

The samples of water taken for examination were derived from the

following sources:--

A. Water supplied by the New River Company.

B. Water supplied by the East London Company.

C. Water from a spring in the neighbourhood of Haslemere, Surrey.

D. Water from a well in Bishopsgate-street.

A. This water was taken from an upright pipe in a court-yard of the

Guildhall. It was slightly opalescent, inodorous, and tasteless;

numerous small particles floated in it, which took a considerable time

to subside. The matter deposited was of a rust colour, and consisted

of peroxide of iron, with a little sulphate and carbonate of lime, and

organic matter. It is to be observed that, as the water from this pipe

is seldom used, these impurities collect in the pipe, and are

therefore in some measure accidental, although, prior to collecting

the water, a considerable quantity had been allowed to run away. The

water was allowed to free itself from these impurities by subsidence,

before being submitted to analysis.

By evaporation to dryness, an imperial gallon left a solid residue,

weighing 17·33 grs., which consisted of--

Carbonate of lime, with a little oxide of iron 11·12

Carbonate of magnesia 0·60

Sulphate of lime 1·56

Chloride of sodium 2·40

Silicic acid 0·37

Organic matter 1·19

-----

17·24

When heated, this water became turbid; and, by continued boiling for

two hours in an apparatus so arranged that the whole of the steam was

condensed and returned to the water, 10·95 grs. of the earthy

carbonates, coloured by oxide of iron, were deposited.

The relative hardness of this water, as determined by the soap test,

distilled water being taken as unity, was 13·3.

* * * * *

B. The second sample of water was taken from a small tap in the house

of Mr. Hall, Bishopsgate-street. The tap was attached to the main.

This water was without smell or taste, and free from floating matter.

After standing some time, it deposited a very small quantity of oxide

of iron. Although clear and transparent, it was not bright.

It contained 19·10 grs. of solid matter in the imperial gallon. The

solid matter consisted of--

Carbonate of lime, with a little oxide of iron 14·58

Carbonate of magnesia 0·44

Sulphate of lime 1·54

Chloride of sodium 1·71

Silicic acid 0·32

Organic matter 0·72

-----

19·31

Like the preceding water it became turbid when heated to the boiling

point, and by continued ebullition for two hours, 12·90 grs. of

carbonate of lime, coloured by oxide of iron, were precipitated.

Hardness in reference to distilled water as unity = 19.

* * * * *

C. This water was taken by ourselves from a spring-head near

Haslemere, Surrey. The spring issued from the foot of a low sand-hill

covered with bushes, and was received into a natural basin about four

or five feet in diameter, the bottom of which was lined with pebbles

and small gravel. From this basin the water flowed into a large

shallow pond.

The temperature of the spring at its source was 49° Fahr., that of the

air being 56° Fahr.

This water was perfectly clear and brilliant, but not sparkling. It

had no appreciable taste, but was peculiarly soft and agreeable. It

did not contain carbonic acid in a free state, for when mixed with a

solution of chloride of calcium and of ammonia not the slightest

turbidity was produced. When boiled it did not lose its transparency,

nor produce any deposit, until concentrated to about one-sixth of its

volume, when glittering scales of hydrated silicic acid separated.

An imperial gallon, when evaporated to dryness, left a solid residue,

which weighed 5·24 grs.

This residue was perfectly white when dried at 300° Fahr.; when heated

to low redness, it charred slightly at the edges. The quantity of

organic matter was therefore exceedingly small.

Hardness in reference to distilled water as unity = 2·4.

On analysis, an imperial gallon was found to contain--

Carbonate of lime 2·00

Chloride of sodium 1·46

Sulphate of soda 0·407

Silicic acid 1·143

Organic matter 0·23

-----

5·24

Traces of an alkaline nitrate were also detected.

During the short visit I made with you to Farnham, we examined several

other springs near to their sources. In their general characters these

waters closely resembled the preceding sample, all of them being

remarkably soft, clear, transparent, inodorous, and free from any

excess of organic matter, or of oxide of iron.

By your desire two samples were subsequently sent to me; one marked

‘Barford,’ the other ‘Boorley.’

The water marked Barford contained 6·30 grs. of solid matter in the

imperial gallon; when evaporated, scales of silicic acid separated

from it in the same manner as from the water taken at Haslemere.

Neither of these waters contained any trace of carbonic acid. Their

relative hardness (distilled being unity) was--Barford 2·4, Boorley

1·5.

* * * * *

D. The fourth sample of water was drawn from the pump near the church

in Bishopsgate-street.

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.

* * * * *

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.

* * * * *

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.

* * * * *

Reports Relating to the Sanitary Condition of the City of London · 第 14 / 26 段