LEAD.

This metal appears to have been known in the earliest ages; and is

mentioned several times by _Moses_.[346] It has a bluish-white colour;

is very brilliant when first cut with a knife, but soon tarnishes by

exposure to air; when rubbed violently, it emits a peculiar smell; it is

malleable and ductile, but possesses very little tenacity. It is

scarcely sonorous; being the softest of all the metals, it yields

readily to the hammer. Its specific gravity is 11·35; it melts at 612°.

According to the experiments of _Dr. Thomson_,[347] it is susceptible of

four degrees of oxidation, presenting us with four distinct, and well

defined oxides, viz.

Yellow (_protoxide_) contains of lead 91·5 oxygen 8·5

Yellow (_deutoxide_) contains of lead 90·5 oxygen 9·5

Red (_tritoxide_) contains of lead 88· oxygen 12·

Brown (_peroxide_) contains of lead 80· oxygen 20·

Lead, in its metallic state, does not exert any action on the living

system; but, when oxidized, or in the state of salt, its virulence is

very considerable, producing a train of symptoms, so peculiar to itself,

as to justify our placing its preparations in a separate class, under

the title of _astringent_ poisons, as explained at page 202.

Metallic lead, although _per se_ inert, may occasion deleterious effects

when introduced into the stomach, in consequence of its meeting with

acids in the _primæ viæ_; from the same cause, liquids which are liable

to become in any degree acidulous, if kept in leaden vessels, may be

productive of much danger to those who drink them. Pure water, provided

the air be excluded, does not appear to exert any sensible action upon

this metal; but the combined influence of these agents converts the lead

into a carbonate: a fact which is at once exemplified by the white line

which is so constantly visible at the surface of the water preserved in

leaden vessels. So well acquainted were the ancients with this fact,

that we find frequent allusions in their works to the dangerous property

of leaden utensils. _Vitruvius_[348] published a very strong

remonstrance against leaden pipes, when used for the purpose of

conveying water; and _Galen_ cautions us continually, not to employ

water that has flowed through pipes of this metal; since he had observed

that the _sediment_ of such water, (υποσταθμη του τουιουτου υδατος)

rendered such as swallowed it, δυσεντερικους, subject to disorders in

the intestines.

_Dr. Lambe_, to whom we are indebted for an important work[349] upon

this subject, states, that there is a great diversity in the corrosive

powers of different waters; in some places the use of leaden pumps has

been in part discontinued, from the expense entailed upon the

proprietors by the perpetual want of repair;[350] and if any acidity be

communicated to the water, from the accidental intrusion of decayed

leaves or other vegetable matter, its power of dissolving this metal

will be increased to a very dangerous extent. The noted colic of

Amsterdam is said by _Tronchin_, who has written a history of the

epidemic, to have been occasioned by leaves falling and putrefying in

leaden cisterns, filled with rain water. _Van Swieten_[351] has also

related an instance of a whole family who were afflicted with colic from

a similar cause; and _Dr. Lambe_[352] entertains no doubt but that the

very striking case recorded in the Medical Commentaries,[353] proceeded

more from some foulness in the cistern than from the solvent power of

the water; in this instance, the officers of a packet vessel used water

out of a leaden cistern; the men also drank the same water, except that

the latter had been kept in wood; the consequence was, that all the

officers were seized with colic, while the men remained healthy. _Sir

George Baker_ has furnished the following striking illustration of the

subject. “The most remarkable case that now occurs to my memory, is that

of _Lord Ashburnham’s_ family, in Sussex; to which, spring water was

supplied from a considerable distance in leaden pipes. In consequence,

his lordship’s servants were every year tormented with colic, and some

of them died. An eminent physician of Battle, who corresponded with me

on the subject, sent up some gallons of that water, which were analysed

by _Dr. Higgins_, who reported that the water had contained more than

the common quantity of carbonic acid; and that he found in it lead in

solution, which he attributed to the carbonic acid. In consequence of

this representation, _Lord Ashburnham_ substituted wooden for leaden

pipes; and from that time his family have experienced no particular

complaints in their bowels.”

But the most extensive and dangerous source of poisoning by lead, is the

presence of this metal in various wines, and acescent drinks, and meats,

and which may arise either from accident or design. A knowledge of the

different avenues, through which this poison may gain admittance into

the human body, is therefore of great importance to the forensic

physician, and we shall accordingly proceed to the investigation of the

subject.

That certain wines were occasionally liable to produce endemic colics,

is a fact which has been long known; although the disease was

universally ascribed to a mistaken origin, until the publication of the

elaborate researches[354] of _Sir George Baker_, into the cause of the

Devonshire colic; which, like the same disease observed in other

countries, was attributed to the acidity of the liquor so abundantly

drunk[355] in these districts. This celebrated physician, however, was

early led to entertain doubts with respect to the truth of this

doctrine: “when I consider,” says he, “that this colic of Devonshire is

precisely the same disease as that which is the specific effect of all

saturnine preparations, and that there is not the least analogy between

the juice of apples and the poison of lead, it seems to me very

improbable that two causes, bearing so little relation to one another,

should make such similar impressions on the human body.” The

investigation of the subject completely established the justness of

these views; and no doubt remains, but that the endemic colic, which

harrassed the cyder drinkers in Devonshire for some years, was the

effect of saturnine impregnation, derived from the lead used in the

construction of the apple mills and cyder presses; and in some cases,

from the pernicious practice of introducing a leaden weight into the

cask, or even racking the cyder into leaden cisterns, where the liquor

fretted too much, and was thereby in danger of becoming acetous. _Sir G.

Baker_ also states that the custom of boiling the _must_ in vessels

capped with lead, affords another source of saturnine impregnation; and

he informs us that, a few years ago, this very practice produced the

_Devonshire colic_ in the county of Kent. Some cyder, which had been

made in a gentleman’s family, being thought too sour, was boiled with

honey in a brewing vessel, capped with lead. All, who drank this liquor,

were seized with this disease; some more, others less violently; one of

the servants died very soon in convulsions: several others were cruelly

tortured a long time. The master of the family, notwithstanding all the

assistance which art could give him, never recovered his health; but

died miserably, after having for nearly three years languished under a

tedious and incurable malady. _Dr. Lambe_ observes, that the saturnine

colic is not endemial in Devonshire, or the other cyder countries,

during the whole year, but is confined to those months when the liquor

is still new, crude, and the fermentation incomplete. When the liquor

becomes fine, the noxious matter in a great measure separates, and is

carried to the bottom of the vessel, as the feculencies subside. Tartar

is generated during the vinous fermentation, the acid of which, uniting

with the lead, forms a salt, scarcely, if at all, soluble in water; and

hence the purification which the liquor receives. But although this new

salt is insoluble in water, it is otherwise in regard to vinegar; for

this acid dissolves a small quantity, and forms a triple compound, an

_aceto-tartrate of lead_;[356] and since no cyder, or perhaps wine, is

wholly destitute of vinegar, it necessarily follows that if the liquor

has been once contaminated during the first stages of fermentation, it

is impossible for it ever to become entirely pure, except by processes

which would render it unfit for drinking.[357] It has very lately been

discovered, that _Gallic acid_ and _tannin_ are capable of combining

with lead in solution, and of forming a perfectly insoluble substance,

which falls to the bottom of the cask; hence all liquors which have been

kept in oak casks, for a certain time, must be freed from lead. This

explains a fact with respect to the effect of new rum in the West

Indies, of some importance. This spirit, when newly distilled, is found

to contain traces of lead, derived from the leaden rims of the coppers,

and the leaden worm, used for its condensation; but, by keeping about

twelve months in oaken casks, it loses its deleterious properties, and

no longer exhibits any traces of this metal.[358]

Another source, from which acescent liquids may contract saturnine

impregnation, is afforded by the metallic glazing of earthenware[359];

that for instance of the common _cream coloured_ ware is composed of an

oxide of lead,[360] and is accordingly easily acted upon by vinegar, and

saline compounds; jars and pots of this description ought therefore

never to be used for preserving pickles, jellies of fruits, marmalade,

and similar conserves. For the same reason, _Sir George Baker_ protests

against the custom of baking fruit tarts in such ware.[361] _Stone ware_

is glazed with muriate of soda, and is therefore not liable to such an

objection.[362]

The custom which prevails in some parts of England of keeping milk in

leaden vessels, is extremely improper; _Dr. Darwin_[363] has illustrated

this subject by the following case; “A delicate young girl, the daughter

of a dairy farmer, who kept his milk in leaden cisterns, used to wipe

off the cream from the edges of the lead, and frequently, as she was

fond of cream, licked it from her finger. She was seized with the

saturnine colic, and semi-paralytic wrists, and sunk from general

debility.” We are informed by _Mr. Parkes_,[364] that in Lancashire the

dairies are furnished with milk-pans made of lead; and that when he

expostulated with some individuals on the danger of this practice, he

was told that _leaden_ milk pans throw up the cream much better than

vessels of any other kind.

There is, says _Dr. Darwin_, a bad custom in almost all families, and

public houses, of washing out their wine bottles by putting a handful of

shot corns into them, and by shaking them about forcibly to detach the

super-tartrate of potass from their sides; that such a practice may

occasionally give origin to serious consequences, will become evident by

the relation of the following case.[365] “A gentleman who had never in

his life experienced a day’s illness, and who was constantly in the

habit of drinking half a bottle of Madeira after his dinner, was taken

ill three hours after dinner with a serious pain in the stomach and

violent colic, which gradually yielded within twelve hours to the

remedies prescribed by his medical attendant. The day following he drank

the remainder of the same bottle of wine which was left the preceding

day, and within two hours afterwards he was again seized with the most

violent pains, head-ache, shiverings, and great pain over the whole

body. His apothecary becoming suspicious that the wine he had drunk

might be the cause of the disease, ordered the bottle, from which it had

been decanted, to be brought to him, with a view that he might examine

the dregs, if any were left. The bottle happening to slip out of the

hand of the servant, disclosed a row of shot, wedged forcibly into the

angular bent-up circumference of it. On examining the beads of shot,

they crumbled into dust, the outer crust (defended by a coat of black

lead with which the shot is glazed) being alone left unacted on, whilst

the remainder of the metal was dissolved. The wine, therefore, had

become contaminated with _lead_, and perhaps _arsenic_, for in order to

form shot the former metal is alloyed with the latter.”[366]

But we have, hitherto, only directed the reader’s attention to the

different sources from which wine, and acescent liquors, may

_accidentally_ derive saturnine impregnation. We have now to state that

such liquors have, in different ages and countries, been fraudulently

adulterated with lead. It appears to have been early discovered, that

wines which have become morbidly acescent may be corrected by the

addition of lead; whence, in those countries where Rhenish, Moselle, and

other similar wines are drunk, the saturnine colic has been endemic. The

celebrated colic which raged in the province of _Poitou_, towards the

end of the sixteenth, and in the beginning of the seventeenth century,

was evidently the effect of such adulteration.[367] We find that, in the

year 1487, there was a _Recessus Imperii_ promulgated at Rotenberg; and,

in the year 1498, at Friberg; which was enacted, in the year 1500, at

Tubingen; and, in the year 1508, at Frankfort; and, in the year 1577, in

the same place. By which decrees it was made a capital crime to

adulterate wines with _litharge_, or to use _bismuth_ in the fumigation

of them; it having been, at several periods, represented to the

Emperors, that great mischief had accrued from such adulterations; and

that they had been the cause of insuperable and mortal diseases. It

should seem, that these laws were not carried into strict execution;

and, indeed, that in the latter end of the seventeenth century, it was

hardly known in Germany that such laws existed. In consequence of which,

an epidemic colic arose, which was at length traced to the effects of

lead in the wines.[368] A representation of this fact having been made

to the _Duke of Wirtemberg_, it was ordained a capital crime to mix

litharge with wine, or even to sell it in the shops, by a decree,

bearing date March 10, 1696. But, notwithstanding the severity of this

law, we are informed by _Zeller_, that in the year 1705, the same

dangerous experiments were repeated in the circle of _Zwaabe_, with a

view to correct the acidity of the weaker wines. _Bishop Watson_[369]

informs us that, in the year 1750, the _Farmers general_ in France being

astonished at the great quantities _de vin gaté_ which were brought into

Paris, in order to be made into vinegar, redoubled their researches to

find out the cause of the great increase in that article; for nearly

thirty thousand hogsheads had been annually brought in for a few years

preceding the year 1750, whereas the quantity annually brought in forty

years before, did not exceed 1200 hogsheads. They discovered that

several wine merchants, assuming the name of vinegar merchants, bought

these sour wines, and afterwards, by means of litharge, rendered them

potable, and sold them as genuine wines.[370] _Dr. Warren_[371] has

related the cases of thirty-two persons in the _Duke of Newcastle’s_

family, who were residing in Hanover in June, 1752, and were seized with

the _Colica Pictonum_, after having used, as their common drink, a small

white wine that has been adulterated with lead. Nor has the English

vintner been less regardless of the health of his employer. In a popular

work on wine making by _Graham_,[372] which has gone through six

editions, and may therefore be supposed to have done some mischief, we

find under the article of _vintner’s secrets_, the following receipts.—

“_To hinder wine from turning_,

“Put a pound of melted lead, in fair water, into a cask, pretty warm,

and stop it close.”

“_To soften green wine_,

“Put in a little vinegar, wherein litharge has been well steeped, and

boil some honey to draw out the wax. Strain it through a cloth, and put

a quart of it into a tierce: and this will mend it, in summer

especially.”

We have already alluded to the presence of lead[373] in the _new_ rum of

the West Indies, as the cause of the disease known in that country by

the name of the _dry belly-ache_; it remains for us to state that the

excise officers frequently avail themselves of the peculiar power of the

_sub-acetate of lead_ to precipitate colouring matter, in order to

remove from seized Holland gin, the colour which it obtains by being

long kept in the tubs in which it is smuggled over. A practice which it

is said renders the gin liable to gripe.

According to the important experiments of _Proust_,[374] it appears,

that if lead be associated with tin, it will be incapable of furnishing

to acids any saturnine impregnation. The following are the interesting

conclusions at which this philosopher has arrived, viz.

“That the _tinning_, which contains even so large a proportion as an

equal part of lead, cannot be dangerous; since it is sufficient that the

lead should be combined with tin, in order to prevent it from being

dissolved, either in lemon juice, or vinegar, the two acids most to be

feared. The tin, being more oxidable than the lead, dissolves

exclusively in these acids, and prevents the second from being attacked.

_The lead cannot appropriate to itself an atom of oxygen, but the tin

would carry it off in an instant._”

SUGAR OF LEAD—_Saccharum Saturni_—_Cerussa Acetata_—_Plumbi

Super-acetas_.

This salt of lead, to whose presence the numerous accidental maladies

above enumerated are to be chiefly attributed, occurs in commerce in the

form of irregular masses resembling lumps of sugar, being an aggregation

of acicular four-sided prisms terminated by dihedral summits; its taste

is sweet and astringent. It is soluble in 25 parts of water, hot, or

cold; when common spring water, however, is employed for such a purpose,

a white precipitate occurs from the presence of a certain proportion of

_sulphates_ and _carbonates_.

When this salt is exposed to the action of heat, it undergoes aqueous

fusion, then dries, and at length is decomposed, leaving a globule of

metallic lead, mixed with the yellow protoxide, and an acid product of a

fetid smell. This decomposition is similar to that which vegetable

substances undergo when heated for some time. The quantity of metallic

lead, thus obtained, will be more considerable if the salt has been

previously mixed with charcoal, and particularly if it be submitted for

a long time to the action of a powerful heat. The strong sulphuric acid

of commerce, when poured upon _sugar of lead_ in powder, decomposes it

with effervescence, and disengages vapours of acetic acid.

This must be considered as an active preparation, and may, when

administered in doses of a few drachms, speedily occasion death. At the

same time, like other poisons, it may by judicious administration,

become a valuable remedy. See _Pharmacologia_, art. _Plumbi

Super-acetas_.

In consequence of the sweet taste of this salt, children have been

induced to swallow it.