This red oxide of lead is easily distinguished by its colour, weight,
and the facility with which it yields metallic lead, when heated with
carbonaceous matter. Common red wafers, which derive their colour from
this oxide, afford a striking illustration of this fact, for if burnt in
a candle, globules of metallic lead will be observed to flow from them.
It is poisonous; and we have already alluded to a case where Gloucester
cheese[377] occasioned deleterious effects, in consequence of its
adulteration with _red lead_. (p. 277) It is destructive also to
inferior animals, apparently in very small quantities; red wafers prove
poisonous to birds who may pick them up; and the same paste is sold for
the purpose of destroying beetles, in which it succeeds very
effectually. Since it is employed as a pigment, it may on many occasions
prove an accidental cause of poisoning; there is indeed one very common
and dangerous source, mentioned by _Sir George Baker_,[378] which
deserves to be particularized in this place, viz. the practice of
painting toys with _red lead_, and other poisonous substances; children,
observes this distinguished physician, are apt to carry every object
which gives them delight to their mouths, the painting of toys,
therefore, with poisonous colours, is a practice which ought to be
abolished, and is the more open to censure, as it is of no real utility.
_Symptoms of poisoning by the different preparations of Lead._
The effects of this poison will vary considerably according to the
quantity swallowed, and the circumstances under which it is taken. We
shall, therefore, first consider its operation, in doses sufficiently
large to occasion at once violent effects; and then describe its agency
as an _accumulative_ poison, where it is introduced into the system
gradually, and in small quantities, so as to act slowly and
imperceptibly, and to lay the foundation of irreparable mischief, before
any alarm is occasioned.
1. _Symptoms which follow a large dose._ Where a salt of lead has been
taken in a considerable dose, the patient soon experiences excruciating
pains in the abdomen, accompanied with sickness and vomiting; the colic
increases to a violent degree, but admits of temporary alleviation by
pressure, a circumstance which at once distinguishes it from the effects
of corrosive poison. Although it is necessary to observe, that
inflammatory symptoms may afterwards occur, where the dose has been very
considerable, and the consequences direct and speedy.
The patient describes the pain as if produced by a boring instrument,
and the abdominal muscles become knotted, and sometimes painfully
retracted with all the contents of the abdomen towards the spine.[379]
The sphincter muscles of the bladder and anus are always affected;
sometimes strangury and tenesmus are the consequences; at other times, a
total incapacity of making any water at all, and so great a contraction
of the sphincter ani that a clyster can hardly be introduced. After
suffering these torments for a period of an indefinite duration,
delirium and cold sweats may supervene, and the patient die in
convulsions. If, however, the treatment has been prompt and judicious,
and the quantity of poison has not been excessive, he may recover from
its immediate effects, and live to testify the severity of the
consecutive phenomena. A most inveterate constipation of the bowels will
continue for a considerable period, and there will be an occasional
recurrence of colic; at length a peculiar species of palsy will
supervene in the upper extremities, especially affecting the muscles of
the fore arm, and wrist,[380] _Citois_ has given us a striking
description of this stage of the saturnine disease. “_Per vicos, veluti
larvæ, aut arte progredientes statuæ, pallidi, squalidi, macilenti
conspiciuntur, manibus incurvis et suo pondere pendulis, nec nisi arte
ad os et cæteras supernas partes sublatis, ac pedibus non suis, sed
crurum muculis, ad ridiculum, ni miserandum, incessum compositis, voce
clangosa et strepera._” It does not appear that the train of symptoms
above described has ever been excited by any other external cause than
the one here assigned. Whenever we meet with colic, attended with
paralytic symptoms of the extremities, we may at once conclude that it
has arisen from the influence of lead.
The disease has been described by authors under the name of the _colic
of Poitou_,[381] or _colica Pictonum_,[382] from the circumstance of its
having raged with such epidemic fury in that province, in consequence of
the adulteration of its wines with lead. It is also mentioned as the
painter’s colic, since this class of artists is very commonly visited by
the disease, in consequence of the _white lead_ contained in their
pigments. At the Lead Hills, it is known to the miners, under the
provincial name of _milreek_; and in Derbyshire, under that of
_belland_.[383]
2. _Symptoms arising from the introduction of lead into the system, by
small and repeated doses._
The effects produced upon various artists by the imperceptible operation
of lead, sufficiently shew the power which this metal possesses of
accumulating in the human system, and it is probable, says _Sir George
Baker_, that from an observation of such slow, but certain effects of
lead, the French and Italians derived the hint of preparing their
celebrated poisons, called “_Poudres de Succession_;”[384] the basis of
which has been supposed to have been some preparation of that mineral.
_Zeller_ mentions a certain chemical operator, near the confines of
Bohemia, who, after having diligently applied himself to the composition
of poisons, did, by means of lead, combined with some more volatile and
corrosive substance, prepare a most slow poison, which given to dogs and
other animals, had the power of destroying them, without producing any
violent symptoms, after several weeks, or even months.[385]
The following-curious case,[386] communicated by _Dr. Wall_, of
Worcester to _Sir George Baker_, will serve to illustrate the present
subject, and to shew that lead may gain admittance into the human body,
unobserved, and even unsuspected. “A gentleman of Worcester was the
father of a numerous offspring, having had one and twenty children, of
whom eight died young, and thirteen survived their parents. During their
infancy, and indeed until they had quitted the place of their usual
residence, they were all remarkably unhealthy; being particularly
subject to disorders of the stomach and bowels. The father, during many
years, was paralytic; the mother, for as long a time, subject to colics
and bilious obstructions. She died at last of an obstinate jaundice.
This disease had been several times removed by the use of the Bath
water; but it always came on again soon after her return to Worcester;
and at last eluded every method and medicine which was tried. After the
death of these parents, the family sold the house which they had so long
inhabited. The purchaser found it necessary to repair the pump. This was
made of lead; and, upon examination, was found to be so corroded, that
several perforations were observed in the cylinder, in which the bucket
plays; and the cistern in the upper part was reduced to the thinness of
common brown paper, and was full of holes like a sieve. The waters of
this town are remarkably hard. It is then more than probable that the
water of this pump, thus impregnated with lead, occasioned the
unhealthiness of the family who drank it. I have been just informed by
the plumber,” adds _Dr. Wall_, “that he had several times repaired the
pump in question; and that he had done so not more than three or four
years before the gentleman’s death; when he found it nearly in the same
state as it has been described; so that the corrosion was effected in a
short time; and consequently the water must have been very strongly
impregnated with the noxious quality of the metal.”
_Organic lesions discovered on dissection._
The reports of the dissection of those who have been destroyed by
saturnine poisons are far from being satisfactory. Where the person has
died from the primary effects of a large dose of the acetate of lead,
the stomach has betrayed a state of inflammation, similar to that which
results from the action of a corrosive poison; black points and spots,
from venous extravasation, have been also observed in the interior of
this viscus; _M. Orfila_ states that he has seen in the stomach of
animals who have taken a large dose of the acetate of lead, and have not
vomited, a membraneous lining tolerably thick, of an ash colour, easily
detaching in small pieces; the origin of which appeared to be owing to
the decomposition of a part of the acetate of lead by the mucous,
bilious, and other fluids, contained in this viscus. The mucous membrane
lying under this lining, was of a dark grey colour throughout its whole
thickness, and appeared to have exercised the same action on the acetate
of lead. The case is very different in those who have died from the slow
action of this metal; all anatomists agree in reporting, that in the
_colica pictonum_, the digestive canal exhibits no vestige of
inflammation;[387] but the diameter of the large intestines, especially
that of the colon, is generally contracted; thus displaying the effects
of that operation, which is supposed to be characteristic of the
compounds of lead, and which has bestowed upon them the peculiar
designation of _astringent_ poisons. _Foderé_ states that the mesentery
and its glands; and the lacteal and lymphatic vessels, are inflamed and
obstructed, and the thoracic duct almost obliterated; the liver, spleen,
pancreas, and lungs often inflamed, tumefied and purulent, and even the
heart shrivelled;[388] and the whole body, in consequence of the
constriction of the chyliferous vessels, in a state of complete
marasmus. Upon this passage _Orfila_ makes the following observation.
“We are under the necessity of declaring, that almost all these signs
are wanting in the majority of the cases of simple colic of lead,
terminated by death.” _Fourcroy_, in a note to his translation of
_Ramazzini_, “_De Morbis Artificum_,” observes that the intestines have,
in these cases, been discovered distended by air, parched, and slightly
altered in colour; and that in the larger ones, balls of dry, dark
coloured, excrementitious matter, have been found.
_Physiological action of Lead Poisons._
The preparations of lead seem to act upon the nervous system, destroying
its energy, and thereby producing paralysis. Whether this is effected
through the medium of the circulation, or whether they produce their
effects without being absorbed, appears to us to be a question which has
not hitherto received a satisfactory answer. It must, however, be
admitted that they act upon the alimentary canal, by coming into contact
with its nerves; and in some cases, where the dose of the _acetate_ has
been large, it may have produced death by the local injury which it
inflicted. _Dr. Lambe_ observes upon this subject, that “certain facts
render it probable that lead does not operate entirely through the
medium of the circulation, nor by nervous sympathy; but also topically,
affecting the part to which it is applied more than the other parts of
the body.” This latter position is clearly established by the beneficial
effects occasioned by the topical application of lead to inflamed
surfaces; nor can any doubt exist as to the fact of such applications
having produced local paralysis. There is a paper in the third volume of
the _Medical Transactions_ by _Dr. Reynolds_, in which the case of a
gentleman is detailed, who brought on a temporary paralysis of the
_sphincter ani_, by freely using _Goulard’s_ lotion for the cure of
piles. Foreign writers have also maintained that saturnine applications
have frequently occasioned impotence; for further information upon this
subject the reader may refer to _Istitutione di Medicina Forens: di
Tortosa_, _vol._ 1, _p._ 58; also _Fritze Compend: sopra i Malat.
Vener._ _p._ 189; and _Monteggia Annotat. sopra i Mali Venerei_, _p._
36. _Sir George Baker_ states that he has some reason to doubt, whether
_litharge_, the common basis of our plasters, when used for the purpose
of dressing issues, has not, in certain irritable constitutions,
produced some of the ordinary effects of saturnine preparations taken
internally. There have been instances of children thrown into
convulsions, by _cerusse_, sprinkled on excoriated parts. _Zeller_
quotes, on the authority of _Molingius_, a remarkable instance of the
pernicious effects of _litharge_, externally applied.[389] _Sir George
Baker_ met with a most violent and obstinate colic, which seemed to have
been occasioned by some litharge, mixed in a cataplasm, and applied to
the _vagina_, with a view to allay a troublesome itching; and he says
that he was informed by _Dr. Petit_ that _Goulard’s poultice_ applied
for some time to a patient’s knee, in St. George’s hospital, occasioned
violent pain in the bowels, which did not cease until the poultice had
been removed; nor are authorities deficient to prove, that the
fashionable application of _cerusse_ to the skin has been followed by
obstinate colics, pains, and tremors. We have been desirous of laying
before our readers the above authorities, in proof of the constitutional
effects which may be occasionally produced by the external application
of lead, since the fact has been questioned, and is still considered by
many as involved in doubt and uncertainty. _Dr. Lambe_ is inclined to
believe, that “to the production of the saturnine colic, it is necessary
that the metal should be applied _immediately_ to the stomach and
intestines.” If this hypothesis be just, he excludes nervous sympathy,
as well as absorption, as a proximate cause of saturnine colic; and,
consequently, no dependence can be placed on the accounts given by the
above pathologists with regard to the production of such an effect by
lotions and cataplasms of lead.
_Of the chemical processes, by which the presence of lead may be
detected._
These will necessarily vary according to the different states of
combination in which it may be supposed to exist; we shall, therefore,
proceed to consider the modes of establishing its presence, 1, In
solution in _water_; _wine_; _spirit_; and _oils_. 2. In a state of
mixture with _various solids_. 3. Combined with _solid or liquid
aliments_.
1. _The lead exists in some unknown state of combination in solution in
water._ We are greatly indebted to _Dr. Lambe_[390] for the able
directions which he has afforded us for ascertaining the presence of
minute portions of lead in water; and we recommend the practitioner, who
may be engaged in such an investigation, to peruse his work with
attention. The following are the reagents through which our analysis
must be conducted.
(_a_) _Sulphuretted hydrogen._ A solution of this gas in distilled water
is a very delicate test for lead, throwing down a precipitate of a very
dark brown colour, approaching to black. The competency, however, of
this test to the discovery of very minute quantities of lead, in certain
states of combination, has been questioned by _Dr. Lambe_; who was
enabled to detect the presence of this metal, by other methods, in water
that manifested no indication with _sulphuretted hydrogen_. He detected
it, for instance, in the precipitate occasioned in such water by the
carbonate of potass or soda. In operating on these waters, he noticed
the following appearances.
1. _The precipitate, produced as above stated, when re-dissolved in
nitric acid, formed a dark cloud with sulphuretted hydrogen._
2. _Although the sulphuretted hydrogen formed no cloud, the
precipitate itself became darkened by it._
3. _The precipitate re-dissolved in nitric acid_, (as in 1) _formed,
with sulphuretted hydrogen, a white cloud._
4. _Sulphuretted hydrogen neither formed a cloud, nor darkened the
precipitate._
5. _In the cases 2, 3, 4, if the precipitate be heated to redness, in
contact with an alkaline carbonate; and after dissolving out the
carbonate, it be redissolved in nitric acid; then sulphuretted
hydrogen will form a dark cloud with the solution._ In these
experiments it is necessary that the acid used to redissolve the
precipitate be not in excess; if it should so happen, the excess
must be saturated, before the test is applied. It is better to use
so little, that some precipitate may remain undissolved. The nitric
acid, used in these experiments, should be perfectly pure; and the
sulphuretted hydrogen test should be recently prepared by saturating
distilled water with the gas.
(_b_) _Sulphate of soda, or potass._ This test will produce a white
precipitate in water, containing one hundred-thousandth of its weight of
lead; and is considered by _Dr. Thomson_ as the most unequivocal reagent
of that metal which we possess. “The precipitate is a fine dense powder,
which speedily falls to the bottom, and is not re-dissolved by nitric
acid; no other precipitate can be confounded with it, except _sulphate
of baryta_, and there is no chance of the presence of baryta in solution
in water.”[391]
(_c_) _Muriate of soda._ One of the methods of analysis proposed by _Dr.
Lambe_, consists in precipitating the lead by common salt; but as the
_muriate of lead_ is partly soluble in water, this test cannot be
applied to small portions of suspected water. The precipitate must,
therefore, be collected from two or three gallons, and heated to redness
with twice its weight of carbonate of soda. The alkaline carbonate is
then to be dissolved out, and nitric acid added, in order to saturate
any superfluity; the _sulphuretted hydrogen_ test will then produce its
indication.
(_d_) _Reduction of the metal._ This is undoubtedly the most
satisfactory of all the tests; and, except the trouble of collecting a
large quantity of precipitate, is not embarrassed with any difficulty.
The precipitate may be mixed with its own weight of alkaline carbonate,
and exposed either with, or without, the addition of a small proportion
of charcoal, to a heat sufficient to melt the alkali. On breaking the
crucible, a small globule of lead will be found reduced at the bottom.
The precipitate from about fifty gallons of water yielded _Dr. Lambe_
about two grains of lead.
2. _The lead is dissolved in wine._ For the detection of this dangerous
fraud, the reagent invented by _Dr. Hahnemann_ affords a ready and
convenient test. It consists of water saturated with sulphuretted
hydrogen gas, and acidulated with muriatic acid;[392] this latter
ingredient is added for the purpose of preventing the precipitation of
any iron, which the wine might accidentally contain. This liquor will,
if added in the proportion of one part to two of wine, produce with the
smallest quantity of lead, a dark coloured, or black precipitate; which,
if collected, dried, and fused before the blow-pipe on a piece of
charcoal, will yield a globule of metallic lead. Or we may modify the
experiment by passing a current of sulphuretted hydrogen gas through the
wine, having previously acidulated it with muriatic acid, to prevent the
precipitation of the iron.
A farther proof of the presence of lead in wines is the occurrence of a
precipitate, on adding a solution of the sulphate of soda.
The most satisfactory proof, however, is derived by distilling off the
alcohol, and calcining the residuum with charcoal, in order to obtain
the metallic lead.
The quantity of lead which has been detected in sophisticated wine, may
be estimated at forty grains of the metal in every fifty gallons,[393]
but this will of course be liable to vary with the degree of acidity it
was intended to correct.
3. _The lead is dissolved in oils._ In this case the lead may be
detected by shaking, in a stopped phial, one part of the suspected oil,
with two or three parts of water, impregnated with _sulphuretted
hydrogen_. This test will announce the presence of the deleterious
metal, by occasioning a dark brown, or black colour.
4. _The lead is mixed with alimentary matter._ _M. Orfila_ has furnished
us with the following directions for assaying the matter vomited, or
that which may be found in the digestive canal, after death. “After
having expressed the fluid portion through a piece of fine linen, it
must be assayed by the _tests_, which have been already enumerated as
being capable of detecting the salts of lead; and if the precipitates
obtained are of a nature to induce a belief, that the fluid contains
some preparation of this kind, it must be evaporated to dryness, and
calcined with charcoal in a crucible; when, at the expiration of three
quarters of an hour, metallic lead will be obtained. If all the
experiments made on the fluid portion of the matter vomited, for the
discovery of this poison, should be fruitless, the whole of the solid
portions, previously dried, should then be calcined with potass and
charcoal, by which means metallic lead will be obtained.”