as great an extent of gravel-walk as the space would admit of; the total
length, including the walk round the flower-garden, exceeding a mile.
There is a straight broad walk in the centre, as a main feature from the
principal entrance; an intersecting broad and straight walk to form a
centre to the garden, and to constitute a point of radiation to all the
other walks; and there is a winding walk surrounding the whole. As a
straight walk without a terminating object is felt to be deficient in
meaning, a statute on a pedestal is proposed for the radiating centre
_i._ in _fig. 2_; a pedestal with a vase, urn, or other object, for the
second circle in the straight walk, _fig. 2_, _k_; while the pavilions
_fig. 3_, form terminating objects to the broad cross walk.
As a terminal object gives meaning to a straight walk leading to it, so
it is only by creating artificial obstructions that meaning can be given
to a winding walk over a flat surface. These obstructions may either be
inequalities in the ground, or the occurrence of trees or shrubs in the
line which the walk would otherwise have taken, so as to force it to
bend out of that line. Both these resources have been employed in laying
down the direction of the surrounding walk, though its deviation from a
straight line has chiefly been made in conformity with the varying
position of the trees in the belt already existing. This belt, and also
the trees in the flower-garden, and in other parts of the plan, which
were there previously to commencing operations, and which are left
conformably to Mr. Strutt’s instructions, are shown in the plan, _fig.
4_, p. 75. The point of junction of one walk with another is always
noticeable in an artistical point of view, and affords an excuse for
putting down sculptural or other ornamental objects at these points.
14.—_Boards of Health:—Report on the labours of the “Conseil de
Salubrité” of Paris, from 1829 to 1839._ _By_ M. TREBUCHET.
Before the revolution of 1789, M. Lenoir, one of the last lieutenants of
police of that period, and one of those who most particularly occupied
themselves with the health of the city of Paris, consulted on questions
of health and salubrity two men, _Pia_ and _Cadet de Vaux_, both of them
apothecaries; the last had the title of inspector-general: it was to him
that all matters of health were habitually referred. Later, on the
institution of the prefect of police, in whose hands was vested all that
related to salubrity and the public health, this magistrate consulted
sometimes a physician, sometimes a chemist, sometimes a veterinary
surgeon, according to the nature of the case upon which he had to
determine.
This state of things presented inconveniences so much the more serious
that the number of affairs increasing every day, demanded more unity in
the reports, and more activity in the labours. It was then that the
necessity was felt of establishing a permanent council. Such was the
origin of the “Conseil de Salubrité,” instituted by the prefect of
police, Dubois, the 6th of July, 1802. It was composed of four
members,—Deyeux, Parmentier, Huzard, senior, and Cadet-Gassicourt. In
1803, M. Thouret was called to the council; afterwards, in 1807, Leroux
and Dupuytren; in 1810, M. Pariset replaced M. Thouret, and it was at
the same period that the nomination of Doctor Petit took place. From
that time the men of the greatest consideration sought to have a part in
the labours of the “Conseil de Salubrité.” Thus we see enter
successively M. d’Arcet in 1813; M. Marc in 1815; M. Berard in 1817; the
engineer Girard, and Huzard, junior, in 1819; Pelletier and Juge in
1821; M. Gautier de Claubry and M. Parent Duchâtelet in 1825; MM.
Adelon, Andral, junior, Barruel, and Labarraque, in 1828; Doctor
Esquirol in 1829. The greater part of these men no longer exist. Deyeux,
Parmentier, Huzard, senior, Cadet-Gassicourt, Thouret. Leroux,
Dupuytren, Marc, Girard, Parent-Duchâtelet, Barruel, Esquirol, are no
longer there to direct the labours of the council, to contribute their
long experience and indefatigable activity; but their labours remain to
us, and we can at least draw from them useful instructions, and still
enlighten ourselves by their valuable opinions.
Thus, and with the view to preserve these precious traditions, which
maintain in the council an unity of design so remarkable, the
administration decided from the commencement that their general reports
should be printed.
This publication, which stopped in 1828, and of which the continuance
was greatly desired, has just been resumed by the orders of M. Gabriel
Delessert, prefect of police.
This collection, which is of such general interest, embraces therefore a
period of nearly forty years.
Perhaps we are to congratulate ourselves on the delay which has taken
place in the publication of these reports. In going over these ten years
it becomes more easy to follow the council in the progressive march of
their labours, to perceive that they were all based upon a uniform and
constant jurisprudence; that they had no other end than the preservation
of the public health, the well-devised interest of property and
industry. On this account we have always thought that besides the annual
reports, extremely useful in other respects, but confined within too
narrow a circle, it would be well to publish every ten years a summary,
which, retracing what had been done in that long period, should offer a
wide field of study both to governors and governed.
Since 1829 the reports addressed to the administration, on the numerous
questions which it submitted to the council, amount to 4431. But that of
which there remains no trace are the experiments, often even the
preliminary reports, the trips, and sometimes the journeys, which each
of these reports rendered necessary; labours of which the report is only
a summary, and which impart such great authority to the decisions of the
council.
These decisions relate to three great divisions,—_health_, _salubrity_,
and _industry_. Under _health_ are classed, among other things, the
researches on the adulteration of food, on the vessels used in its
preparation, on the precautions to be taken with respect to the vessels
and utensils of copper, regard being had to the uses for which they are
employed; the experiments on the adulteration of salts, on the
adulteration of bread and of flour by different substances, on the
poisonous substances employed to colour bonbons, liqueurs, &c.; the
examination of the methods employed in preparing pork; the examination
of the water used for drink; the adulteration of the flours of linseed
and mustard; the use of meat of animals who had died of disease; the
researches into the salubrity of dwellings. The head of _salubrity_
comprises the anatomical theatres, their construction, the means of
remedying the causes of the unhealthiness which these establishments
present; the discharge of sulphurous waters from the public baths, the
utility of street fountains, the inspection of barracks, and the
sanitary measures to which they should be subject; the improvements to
be made in the fires of the establishments which employ coals; the
arrangements to be made for the deposit of filth in the rural districts;
the purification of sewers; the supply of water for domestic and
industrial purposes; the steps to be taken in exhumations; the
examination of different contrivances to empty privies, the
ameliorations to be introduced into this portion of service; the
wholesomeness of the markets, the inspection of prisons. The reports
which relate to _industry_ principally treat of the construction of
slaughter-houses; the condensation of the gas and vapours resulting from
the refining of metals; the fabrication, preservation, and sale of
fulminating and lucifer matches; the precautions to be taken in the
construction of fulminating powder-mills, and in the manipulation of the
substances employed there; the measures to be taken for the conveyance
of the fulminate of mercury; the researches into the employment of
bitumens, and the conditions to be prescribed to the makers; the making
wax-candles; the conditions to be imposed on cat-gut factories; the
researches on the fires of wash-houses, and on the necessity of
decomposing the soapy water to prevent putrefaction; the sanitary
measures applicable to white lead manufactories, and the researches on
the diseases of the workmen; the propositions of classification for
different trades, such as the silk-hat factories, the forges, the places
for making and keeping ether; and the beating of carpets.
Thus health, salubrity, industry, offer to the “Conseil de Salubrité” a
vast field of researches and investigations, and we may affirm that
there is no question relating to these three great departments of the
administration which they have not profoundly meditated, and in part
resolved. If now we turn to other subjects we still find important
labours which touch in several points on the different matters of which
we have just spoken, but which have not, like them, a special and
clearly-defined character: such are the reports on epidemics and
small-pox; the measures to be taken to prevent or combat them; the
_epizooties_ that have prevailed at different epochs among several
species of animals, and particularly among milking-cows; the sale of
horses with glanders, and the regulations to which they should be
subject, as well as other animals seized with contagious diseases; the
measures to be taken against mad dogs, and the precautions in case of
bites from these animals; the modelling, examination, and embalming of
corpses; the aids to be afforded to the drowned and suffocated; the
measures to be taken to ascertain the number of these accidents as well
as of suicides; the compilation of a new nosographic table of the
diseases which cause death; the measures to be taken to prevent fires in
theatres, &c. &c.
Such is a general view of the subjects upon which the council has been
called to give their opinions. It now remains to describe the
circumstances which demanded them, and the results they have produced.
One of the objects which more especially engaged the care of the council
was that of bread. It is the thing, it is true, which most directly
interests the people. The quality of bread may be deteriorated by
various ingredients, but no one could have foreseen that noxious
substances would be employed with the view, ostensibly at least, of
improving it. Nevertheless the correctional tribunal of Brussels was
called upon some years since to try some bakers brought before it under
a charge of selling bread adulterated with noxious substances. On the
occasion of this trial the prefect of police inquired of the council if,
as these bakers alleged in their defence, a small quantity of a
substance which they called _blue_ alum, put into the yeast, had the
property of rendering the bread whiter and less heavy.
In order to give their opinion, the council first examined what was the
substance called by the name of _blue_ alum. Some designate by this name
the sulphate of copper, but most people mean by blue alum the rock alum,
(sulphate of alumina and potass,) because this salt in the lump has a
bluish tinge, and, as with all the sulphates, the sulphate of which the
base is alumina is the only one which bears the name of alum, it is to
be presumed that it is this salt, or rock alum, which goes under the
name of _blue alum_, and not the sulphate of copper which is known in
commerce by the name of _blue vitriol_.
It had been long known that alum, by the action of heat equal to that of
a baker’s oven, swells, increases in volume, and becomes a porous mass,
light and very white, which is no longer alum, but a mixture of a great
deal of insoluble sub-sulphate with a small quantity of alum, a
substance astringent, and not poisonous. It is probable that this
property, known to some bakers, determined them to add to bread made of
certain flour a little of this alum, which, without being injurious to
the health, really made the bread whiter, at the same time that the
crust became brown at a less heat.
As to the employment of sulphate of copper (blue vitriol), it is only by
a gross error that it could be supposed capable of making bread white.
Nevertheless a baker of the town of Gand was prosecuted for putting this
poisonous salt into his bread. The commission appointed to examine the
bread not having been able to discover any trace of copper, mixed a
kilogram of flour, to which was added twenty-four grains of sulphate of
copper, and they affirmed that it was impossible to detect in the bread
the least trace of the salt they had introduced.
After such an assertion it became interesting to make some researches on
the subject. In consequence, the delegates of the council who were
entrusted with the inquiry, had four loaves of a kilogram of flour made
under their eyes: in one of these loaves was put twelve grains of
sulphate of copper, in another eight grains, in a third four grains, and
but two grains in the fourth. These loaves rose ill, and although the
flour with which they were made produced bread very beautiful and white,
the four loaves were so heavy as scarcely to present any cavities. The
loaf No. 1 had a green disagreeable colour; the loaf No. 2 was in like
manner green, but of a less deep colour than the preceding; No. 3 was
also greenish; and No. 4, though colourless, could not support a
comparison with the bread made from the same flour pure.
All these loaves were burnt separately in porcelain crucibles to
complete ashes. Those of the loaf No. 1 were a beautiful azure blue;
those of No. 2 a clearer sky-blue; those of No. 3 had a blue tint of a
lighter hue; and those of No. 4 were so slightly coloured that it would
have been impossible to infer that they contained copper. But all these
ashes, when submitted to the action of sulphuric acid diluted with
water, were dissolved, and when tested separately by hydrosulphuric
acid, produced black precipitates of sulphuret of copper, which
precipitates, tested separately in their turn by concentrated nitric
acid, furnished each a quantity of nitrate of copper, equal, within a
few fractions, to the sulphate added to each of the four loaves.
It results, therefore, from the preceding experiments which have been
made with the greatest care,
1. That the sulphate of copper (blue vitriol) cannot be used in making
bread for the purpose of rendering it lighter or whiter, because it
prevents its rising, and gives it a disagreeable colour;
2. That by reducing it to ashes, and employing suitable means, almost
all the salt of copper added to the bread may be collected again.
We should exceed the bounds of this Article if we were to re-produce the
numerous reports on the bread or flour submitted to the analysis of the
council, and especially on the bread and flour destined for the use of
prisons, on mixed flour, and on the quality of bread prepared from flour
mixed with starch. The council after examining this bread remarked, that
it was not disagreeable to the taste, nor liable to injure the health.
However, they were not able to pronounce on its nutritive qualities. It
has therefore been recommended that if bread made of flour so mixed was
offered for sale, it should have a peculiar form, in order that the
public should know what is the nature of the food which is sold to them.
The same conclusions have been come to with respect to the sale of bread
made of flour mixed with a seventh of the flour of rice. This bread is,
according to the council, savoury and it keeps well, and does not become
hard so soon as the bread prepared in the ordinary way. As to its
nutritive qualities, the council cannot determine on this particular,
the question being one of those which, in the actual state of science,
is the most difficult, and which can only be solved by a prolonged use
of the bread. To complete the series of reports on all that concerns
this species of food, we must speak of the leaden reservoirs made use of
by bakers. It was of moment to know whether the employment by the bakers
of Paris of leaden reservoirs to keep the water used in making bread
could give rise to accidents; whether these reservoirs should be
prohibited, or whether they might be allowed with certain modifications?
The council have studied this important question, which is become among
chemists an object of controversy. Some have affirmed that the water
gets charged with oxide of lead by remaining in reservoirs formed of
this metal. Other chemists, of no less repute, and among others Guyton
de Morveaux, have established, on the contrary, that the presence of a
neutral salt, like sulphate, nitrate or muriate, in whatever quantity,
as 000·2, suffices to prevent the water from dissolving the lead; and
they explain in this way the use that is made, without any ill effects,
of the water of the Seine, and of wells, preserved in leaden vessels,
with or without exposure to the air.
This diversity of opinion rendered necessary numerous experiments, which
have been made with the greatest exactness by a commission of the
council. It results from these experiments:—
1. That distilled water put into a reservoir gives rise at the end of
some minutes to the formation of a salt of white-lead, but that this
salt does not dissolve in the water, and is precipitated, on the
contrary, to the bottom of the reservoir.
2. That the waters of the Seine, and of wells, placed in leaden
reservoirs, have given rise, at the point of contact of the water and
air, to the formation of a white saline matter, which does not dissolve
in water but is precipitated to the bottom of the vessel.
3. That the gaseous Seltz water acts the same on the leaden reservoirs
as the water of the Seine, and of wells. Before affirming what precedes,
the commission left some water for several weeks in four leaden
reservoirs. The liquid was almost entirely evaporated, and the remainder
of the water, when filtered, showed no trace of lead on the application
of the most delicate tests, such as the chromate of potash,
hydrosulphuric acid, and hydriodate of potash.
Water which had remained in a bucket, spread over at the moment, and
throughout its whole extent, with a saline matter composed of carbonate
of lead and of lime, of sulphate of lime and organic substances, did not
leave the slightest trace of lead by the action on the water of the most
powerful tests.
In consequence of these experiments, the council pronounced a formal
opinion, that the bakers might be permitted the use of leaden reservoirs
on condition that they put a cock three inches from the bottom of the
reservoir, in order that if the insoluble carbonate formed it might be
deposited in the water below the cock, and with the further condition
that the reservoir should be cleaned once a-month. For greater security,
the council thought that it should be required of bakers to cover over
the lead which lines these reservoirs with a thin coat of wax, which
would prevent the contact of the water with the metal, and stop the
formation of the insoluble carbonate of lead. To apply this wax it is
only necessary to heat slightly the lead, and rub it rapidly and several
times with a piece of wool done over with wax.
Besides these questions which relate to the quality of the bread, the
council examined what mischief could arise from the use of copper scales
to weigh the dough of which the bread is made. It is known that the
dishes of these scales are copper, and that instead of being cleaned
with cloths they are cleaned with the chains by which they are
suspended, and which, for this purpose, are heaped together and act like
a brush. This state of things seriously engaged the attention of the
council with respect to the danger it presents. The dough, composed of
water and flour, and containing in addition a certain quantity of marine
salt, sticks to the dishes of the scales, and exercises on the metal a
chemical action, of which the result is the oxide of copper. The oxide,
or salts of copper, which is formed, next penetrates into the portion of
the dough which is afterwards detached by the friction of the chains.
We may suppose that in this case some of the oxide of copper would be
introduced into the bread, and that it is important for the public
health to take measures to prevent, from negligence or imprudence, bread
which contained even very small quantities of salts of copper, from
being offered for consumption. The council thought that all danger would
be prevented.
1. By compelling the bakers to use no scales but those of which the
dishes were of tinned iron.
2. In prescribing to them to clean the dishes of the scales by means of
chains of tinned iron, which should only be used for this purpose.
3. By obliging them to wash the chains, and the pan in which they are
kept, with warm water.
4. By prohibiting the bakers to employ in their bakehouses utensils of
zinc, or red and yellow copper.
5. By ordering the bakers, if it is not found expedient to impose the
execution of the measures indicated in the first and third articles, to
tin substantially the chains and dishes of their scales, and any
utensils of zinc, or red and yellow copper.
The council have been occupied at different periods with the
adulterations of salt, and they have not ceased to lend active
assistance to the measures of surveillance prescribed by the Government.
Unhappily its efforts were long unsuccessful. Even now the analysis
which has been made of more than 6000 samples of salt, proves that fraud
always exists, although of a kind less detrimental to the public health.
In 1829 the council proposed to forbid the sale of salt which contained
from five to six per cent. of salts with a potash base, and to oppose,
in addition, the sale of salt mixed with sea-weed, even in small
quantities. The council has since renewed their investigations. More
than 3000 samples of salt, taken from the shops, were analysed by M.
Chevalier, who discovered that 309 samples were adulterated by ground
plaster, or salts of potash, or sulphate of soda, or by the iodines.
These adulterations were found chiefly in the grey salts. The later
experiments of the council have confirmed these results. They have,
moreover, shown that the salt derived from the mines of the south is
more pure than the salt of the west. It contains less water, and less of
the insoluble matter foreign to sea-salt.
We wish we could follow the council in their numerous observations on
the filtering of water—on the use of vessels and utensils of copper—on
the dangers they present according to the circumstances in which they
are employed—and on the regulations of which they ought to be the
object; but there still remains much to be extracted, to show their
solicitude for everything which concerns the well-being of the people,
and the preservation of the public health.