Some of the cases of poisoning, especial_Industrial Poisoning from Fumes, Gases and Poisons of Manufacturing Processes

the production of distillation constituents of coal tar are doubtless

attributable to _sulphuretted hydrogen gas_. Thus in England, in the

years 1901-3, there were eleven fatal and as many other severe cases

reported from tar distilleries, of which the majority were due to

sulphuretted hydrogen gas.

One case of _carbonic oxide_ poisoning in coal-tar distillation is

described.[5] In cleaning out pitch from a still fourteen days after the

last distillation a workman succumbed to carbonic oxide poisoning. This

is at all events a rare eventuality, since no other case is to be found

in the literature of the subject, but it is a proof that in the last

stage of coal-tar distillation carbonic oxide plays a part.

Mention must be made of the frequent occurrence of severe skin affections

in _anthracene workers_; they take the form of an eruption on the hands,

arms, feet, knees, &c., and sometimes develop into cancer.

Observations in a chemical factory since 1892 showed that of thirty thus

affected in the course of ten years twenty-two came into contact with

paraffin.

Artificial Organic Dye Stuffs (Coal-tar Colours)

MANUFACTURE.—The starting-points for the preparation of artificial

coal-tar dyes are mainly those aromatic compounds (hydrocarbons)

described in the preceding section. Besides these, however, there are the

derivatives of the fatty series such as methyl alcohol (wood spirit),

ethyl alcohol, phosgene, and, latterly, formaldehyde.

The _hydrocarbons of the benzene series_ from tar distillation are

delivered almost pure to the colour factory. Of these benzene, toluene,

xylene, naphthalene, anthracene, and the phenols, cresols, &c., have to

be considered.

Further treatment is as follows:

1. Nitration, i.e. introduction of a nitro-group by means of nitric acid.

2. Reduction of the nitrated products to amines.

3. Sulphonation, i.e. conversion to sulphonic acids by means of

concentrated sulphuric acid.

4. The sulphonic acids are converted into phenols by fusing with caustic

soda.

5. Introduction of chlorine and bromine.

_Nitro-derivatives_ are technically obtained by the action of a mixture

of nitric and concentrated sulphuric acids on the aromatic body in

question. The most important example is _nitrobenzene_.

Benzene is treated for several hours in cylindrical cast-iron pans with

nitric and concentrated sulphuric acids. The vessel is cooled externally

and well agitated. A temperature of 25° C. should not be exceeded.

[Illustration: FIG. 25.—Preparation of Intermediate Products in the

Aniline Colour Industry (Closed Apparatus), showing Arrangement for

Condensation (_after Leymann_)]

On standing the fluid separates into two layers: the lower consists of

dilute sulphuric acid in which there is still some nitric acid, and

the upper of nitrobenzene. The latter is freed of remains of acid by

washing and of water by distillation. _Toluene_ and _xylene_ are nitrated

in the same way. _Dinitro products_ (such as metadinitrobenzene) are

obtained by further action of the nitro-sulphuric acid mixture on the

mononitro-compound at higher temperature.

For conversion of phenol into _picric acid_ (trinitrophenol) the use of a

nitro-sulphuric acid mixture is necessary.

The _aromatic bases_ (aniline, toluidine, xylidine) are obtained by

reduction of the corresponding nitro-compound by means of iron filings

and acid (hydrochloric, sulphuric, or acetic). Thus in the case of

_aniline_ pure nitrobenzene is decomposed in an iron cylindrical

apparatus, provided with agitators and a condenser, and avoidance of a

too violent reaction, by means of fine iron filings and about 5 per cent.

hydrochloric acid. After completion of the reaction the contents are

rendered alkaline by addition of lime and the aniline distilled over.

Manufacture of _toluidine_ and _xylidine_ is analogous.

_Dimethylaniline_ is obtained by heating aniline, aniline hydrochloride,

and methyl alcohol.

_Diethylaniline_ is prepared in an analogous way with the use of ethyl

alcohol.

By the action of nitrous acid (sodium nitrite and hydrochloric acid) on

the acid solution of the last-named compound the _nitroso compounds_ are

formed.

_Sulphonic acids_ arise by the action of concentrated or fuming sulphuric

acid on the corresponding bodies of the aromatic series: benzene

disulphonic acid from benzene and fuming sulphuric acid, &c.

_Phenols_ and _cresols_ are obtained pure from tar distillation. The

remaining hydroxyl derivatives (resorcin, α- and β-naphthol, &c.), are

generally obtained by the action of concentrated caustic soda on aromatic

sulphonic acids.

The most important aromatic aldehyde, _benzaldehyde_, is obtained from

toluene; on introducing chlorine at boiling temperature benzyl chloride

is first formed, then benzal-chloride and finally benzo-trichloride. In

heating benzal-chloride with milk of lime (under pressure) benzaldehyde

is formed (C₆H₅COH).

_Picric acid_ and _naphthol yellow_ belong to the _nitro dyestuffs_; the

last named is obtained by sulphonating α-naphthol with fuming sulphuric

acid and by the action of nitric acid on the sulphonated mixture.

Nitroso derivatives of aromatic phenols yield (with metal oxides) the

material for production of nitroso dyestuffs. To these belong naphthol

green, &c.

The most important _azo dyestuffs_ technically are produced in principle

by the action of nitrous acid on the aromatic amines. The amido compound

is converted into the diazo salt by treatment with sodium nitrite in

acid solution. Thus diazo-benzene is made from aniline. Diazo compounds

are not usually isolated but immediately coupled with other suitable

compounds—amido derivatives, phenols—i.e. converted into azo compounds.

[Illustration: FIG. 26.—Nitrating Plant (_after Leymann_)

I Nitric acid

II Balance

III Storage tank

IV Nitrating pan

V Waste acid tank

VI Acid egg

VII Hydrocarbon

VIII Balance

IX Storage tank

X Washing vessel

XI Centrifugal machine

XII Egg

- - - Exhaust ventilation pipe.]

The combination of the two constituents takes place at once and

quantitatively. The colour is separated from the aqueous solution by

salting-out, and is then put through a filter press. The reactions

are carried out generally in wooden vats arranged in stages. Besides

a second, a third constituent can be introduced, and in this way

naphthol—and naphthylamine sulphonic acids yield a large number of

colouring matters. A very large number of azo dyestuffs can thus be

produced by the variation of the first component (the primary base) with

the second and again with the third component, but it would carry us too

far to deal further with their preparation.

_Anthracene colours_—yielding so-called direct dyes—are prepared

from anthracene, which is converted into anthraquinone by the action

of bichromate and dilute sulphuric acid when heated; the crude

‘quinone’ is purified with concentrated sulphuric acid and converted

into anthraquinone monosulphonic acid to serve in the preparation of

_alizarin_, which is made from it by heating for several days with

concentrated caustic soda to which sodium chlorate is added. The process

is carried on in cast-iron pans provided with agitators.

_Alizarin_ is the starting-point for the alizarin dyes, but of their

production we will not speak further, as they, and indeed most of the

coal-tar dyes, are non-poisonous.

_Indigo_ to-day is generally obtained by synthesis. It is prepared from

phenylglycine or phenylglycine ortho-carboxylic acid, which on heating

with sodamide becomes converted into indoxyl or indoxyl carboxylic

acid. These in presence of an alkali in watery solution and exposure to

the oxygen of the air immediately form indigo. The necessary glycine

derivatives are obtained by the action of monochloracetic acid on aniline

or anthranilic acid, which again are derived from naphthalene (by

oxidation to phthalic acid and treatment of phthalimide with bleaching

powder and soda liquor).

_Fuchsin_ belongs to the group of triphenylmethane dyestuffs, with the

production of which the epoch of coal-tar colour manufacture began, from

the observation that impure aniline on oxidation gave a red colour. The

original method of manufacture with arsenic acid is practically given up

in consequence of the unpleasant effects which use and recovery of large

quantities of arsenic acid gave rise to. The method consisted in heating

a mixture of aniline and toluidine with a solution of arsenic acid under

agitation in cast-iron cylinders. The cooled and solidified mass from the

retorts was boiled, and from the hot solution, after filtration, the raw

fuchsin was precipitated with salt and purified by crystallisation.

Now by the usual nitrobenzene process, aniline, toluidine, nitrobenzene,

and nitrotoluene are heated with admixture of hydrochloric acid and some

iron protochloride or zinc chloride. Further treatment resembles the

arsenic process.

By alkylation, i.e. substitution of several hydrogen atoms of the

amido-groups by ethyl, &c., through the action of alkyl halogens

and others, it was found possible to convert fuchsin into other

triphenylmethane colours. But it was soon found simpler to transfer

already alkylated amines into the colours in question. Thus, for example,

to prepare _methyl violet_ dimethyl aniline was heated for a long time

with salt, copper chloride, and phenol containing cresol in iron mixing

drums. The product is freed from salt and phenol by water and calcium

hydrate, subsequently treated with sulphuretted hydrogen or sodium

sulphide, and the colour separated from copper sulphide by dissolving in

dilute acid.

Mention must be made, finally, of the _sulphur dyes_ obtained by heating

organic compounds with sulphur or sodium sulphide. For the purpose

derivatives of diphenylamine, nitro- and amido-phenols, &c., serve as the

starting-point.

EFFECTS ON HEALTH.—From what has been said of the manufacture of coal-tar

dyes it is evident that poisoning can arise from the initial substances

used (benzene, toluene, &c.), from the elements or compounds employed

in carrying out the reactions (such as chlorine, nitric acid, sulphuric

acid, arsenious acid, sodium sulphide, and sulphuretted hydrogen gas),

from the intermediate bodies formed (nitro and amido compounds, such as

nitrobenzene, dinitrobenzene, aniline, &c.), and that, finally, the end

products (the dyes themselves) can act as poisons. It has already been

said that most of the dyes are quite harmless unless contaminated with

the poisonous substances used in their manufacture.

We have seen that many of the raw substances used in the manufacture

of coal-tar dyes are poisonous, and we shall learn that several of the

intermediate products (especially the nitro and amido compounds) are so

also.

According to Grandhomme,[1] of the raw materials benzene is the one

responsible for most poisoning. He describes two fatal cases of benzene

poisoning. In one case the worker was employed for a short time in a room

charged with benzene fumes, dashed suddenly out of it, and died shortly

after. In the other, the workman was employed cleaning out a vessel in

which lixiviation with benzene had taken place. Although the vessel

had been steamed and properly cooled, so much benzene fume came off in

emptying the residue as to overcome the workman and cause death in a

short time.

Grandhomme describes no injurious effect from naphthalene nor, indeed,

from anthracene, which he considered was without effect on the workers.

Similarly, his report as to nitrobenzene was favourable. No reported case

of poisoning occurred among twenty-one men employed, in some of whom

duration of employment was from ten to twenty years. Aniline poisoning,

however, was frequent among them. In the three years there was a total

of forty-two cases of anilism, involving 193 sick days—an average of

fourteen cases a year and sixty-four sick days. None was fatal and some

were quite transient attacks.

In the fuchsin department no cases occurred, and any evil effects in the

manufacture were attributable to arsenic in the now obsolete arsenic

process. Nor was poisoning observed in the preparation of the dyes in

the remaining departments—blues, dahlias, greens, resorcin, or eosin. In

the manufacture of methylene blue Grandhomme points out the possibility

of evolution of arseniuretted hydrogen gas from use of hydrochloric acid

and zinc containing arsenic. Poisoning was absent also in the departments

where alizarine colours and pharmaceutical preparations were made.

Among the 2500-2700 workers Grandhomme records 122 cases of industrial

sickness in the three years 1893-5, involving 724 sick days. In addition

to forty-two cases of anilism there were seventy-six cases of lead

poisoning with 533 sick days. Most of these were not lead burners, but

workers newly employed in the nitrating department who neglected the

prescribed precautionary measures. Lastly, he mentions the occurrence of

chrome ulceration.

The frequency of sickness in the Höchst factory in each of the years

1893-5 was remarkably high: 126 per cent., 91 per cent., and 95 per

cent. Much less was the morbidity in the years 1899-1906—about 66 per

cent.—recorded by Leymann[2]—probably the same Höchst factory with 2000

to 2200 employed. And the cases of industrial poisoning also were less.

He cites only twenty-one in the whole of the period 1899-1906. Of these

twelve were due to aniline, involving thirty sick days, only five to lead

poisoning, with fifty-four sick days, one to chrome ulceration, one to

arseniuretted hydrogen gas (nine sick days), and one fatal case each from

sulphuretted hydrogen gas and from dimethyl sulphate. In 1899, of three

slight cases of aniline poisoning one was attributable to paranitraniline

(inhalation of dust), and the two others to spurting of aniline oil on

to the clothing, which was not at once changed. Of the four cases in

1900, one was a plumber repairing pipes conveying aniline and the others

persons whose clothes had been splashed.

In 1903 a worker employed for eleven and a half years in the aniline

department died of cancer of the bladder. Such cancerous tumours have

for some years been not infrequently observed in aniline workers, and

operations for their removal performed. Leymann thinks it very probable

that the affection is set up, or its origin favoured, by aniline. This

view must be accepted, and the disease regarded as of industrial origin.

Three slight cases in 1904 and 1905 were due partly to contamination of

clothing and partly to inhalation of fumes. Of the five cases of lead

poisoning three were referable to previous lead employment. Perforation

of the septum of the nose by bichromate dust was reported once only. A

fatal case from sulphuretted hydrogen gas and a case of poisoning by

arseniuretted hydrogen gas occurred in 1906, but their origin could not

be traced.

In large modern aniline dye factories, therefore, the health of the

workers is, on the whole, good and industrial poisoning rare. Comparison

of the two sets of statistics show that improvement in health has

followed on improved methods of manufacture. Such cases of aniline

poisoning as are reported are usually slight, and often accounted for by

carelessness on the part of the workers.

Data as to the health of workers in factories manufacturing or using

nitro compounds are given in the English factory inspectors’ reports

for 1905. Even with fortnightly medical examination in them, more than

half the workers showed signs of anæmia and slight cyanosis. Two men in

a factory employing twelve men in the manufacture of nitro compounds

were treated in hospital for cyanosis, distress of breathing, and general

weakness. One had only worked in the factory for nine days. In another

badly ventilated factory, of twenty persons examined fourteen showed

bluish-grey coloration of the lips and face, ten were distinctly anæmic,

and six showed tremor and weakness of grasp.

Nitrobenzene poisoning arises from the fumes present in aniline and

roburite factories. Acute and chronic poisoning by nitro compounds of

the benzene series are described, brought about by accident (fracture

of transport vessels) and by carelessness (splashing on to clothes).

Cases of optic neuritis (inflammation of the optic nerve) as a result of

chronic nitrobenzene poisoning are described.

Dinitrobenzene and other nitro and dinitro compounds are present

in safety explosives. Thus roburite and bellite consist of

metadinitrobenzene and ammonium nitrate; ammonite of nitronaphthalene and

ammonium nitrate; securite of the materials in roburite with ammonium

oxalate in addition. In roburite there may be also chlorinated nitro

compounds.

Leymann,[3] describing accidents in the preparation of nitrophenol

and nitrochloro compounds, mentions four fatal cases occurring in the

manufacture of black dyes from mono- and di-nitrophenols as well as

mono- and di-nitrochlorobenzene and toluene. In three of the cases

dinitrophenol was the compound at fault owing to insufficient care in

the preparation,—the result of ignorance until then of risk of poisoning

from mono- and tri-nitrophenol. One of the men had had to empty a washing

trough containing moist dinitrophenol. He suddenly became collapsed, with

pain in the chest, vomiting, fever, and convulsions, and died within

five hours. Another suffered from great difficulty of breathing, fever,

rapid pulse, dilatation of the pupils, and died within a few hours in

convulsions. Two further cases of nitrochlorobenzene poisoning are

referred to, one of which was fatal. Four chlorobenzene workers after a

bout of drinking were found unconscious in the street, and only recovered

after eight to ten hours in hospital. The symptoms were grey-blue colour

of the skin, pallor of mucous membranes, lips, nose, and conjunctivæ,

and peculiar chocolate-coloured blood.

Many cases of poisoning from roburite are recorded.[4] In the Witten

roburite factory it is stated that during the years 1890-7 almost all

the workers had been ill.[5] Only three looked healthy—all the others

suffered from more or less pallor, blue lips, and yellowish conjunctivæ.

A case of chlorobenzene poisoning was reported with symptoms of headache,

cyanosis, fainting attacks, difficulty of breathing, &c., in a man who

had worked only three weeks with the substance.[6]

In the nitrotoluene department of an explosives factory a number of

the workmen suffered from symptoms of distress in breathing, headache,

&c., of whom two, employed only a short time, died. The poisoning was

attributed, partly to nitrotoluene and partly to nitrous fumes. As a

contributing cause it was alleged that in view of shortage of hands

unsuitable persons were engaged who neglected precautions.[7]

Nitronaphthalene is said to cause inflammation and opacity of the

cornea,[8] attributable either to long-continued exposure (four to eight

months) to nitronaphthalene vapour or to spurting of the liquid into the

eye.

I could not find reference in literature to actual cases of poisoning by

picric acid. They are referred to in a general way only as causing skin

affections.

Aniline poisoning arises generally from inhalation, but absorption

through the skin and less frequently inhalation of dust of aniline

compounds cause it. We have already laid stress on the frequently severe

cases resulting from carelessness in spilling on to or splashing of,

clothes without at once changing them, breaking of vessels containing it,

and entering vessels filled with the vapour. In literature of old date

many such cases have been described, and it was stated that workers were

especially affected on hot days, when almost all showed cyanosis. Such

observations do not state fairly the conditions to-day in view of the

improvements which Grandhomme and Leymann’s observations show have taken

place in aniline factories. Still, cases are fairly frequent. Thus in a

factory with 251 persons employed, thirty-three cases involving 500 days

of sickness were reported.

The Report of the Union of Chemical Industry for 1907 cites the case of a

worker who was tightening up the leaky wooden bung of a vessel containing

aniline at a temperature of 200° C. He was splashed on the face and arms,

and although the burns were not in themselves severe he died the next day

from aniline absorption.

Cases of anilism are not infrequent among dyers. The reports of the

Swiss factory inspectors for 1905 describe a case where a workman worked

for five hours in clothes on to which aniline had spurted when opening

an iron drum. Similar cases are described in the report of the English

factory inspectors for the same year. Aniline black dyeing frequently

gives rise to poisoning, and to this Dearden[9] of Manchester especially

has called attention.

Typical aniline poisoning occurred in Bohemia in 1908 in a cloth presser

working with black dyes. While crushing aniline hydrochloride with

one hand, he ate his food with the other. That the health of persons

employed in aniline black dyeing must be affected by their work is shown

by medical examination. For instance, the English medical inspector of

factories in the summer months of 1905 found among sixty persons employed

in mixing, preparing, and ageing 47 per cent. with greyish coloration of

lips and 57 per cent. characteristically anæmic. Further, of eighty-two

persons employed in padding, washing, and drying, 34 per cent. had grey

lips, 20 per cent. were anæmic, and 14 per cent. with signs of acute or

old effects of chrome ulceration. Gastric symptoms were not infrequently

complained of. The symptoms were worse in hot weather.

Use of aniline in other industries may lead to poisoning. Thus in the

extraction of foreign resins with aniline seventeen workers suffered

(eleven severely). Interesting cases of poisoning in a laundry from use

of a writing ink containing aniline have been recorded.[10]

Reference is necessary to tumours of the bladder observed in aniline

workers. The first observations on the subject were made by Rehn of

Frankfurt, who operated in three cases. Bachfeld of Offenbach noticed in

sixty-three cases of aniline poisoning bladder affections in sixteen.

Seyberth described five cases of tumours of the bladder in workers

with long duration of employment in aniline factories.[11] In the

Höchst factory (and credit is due to the management for the step) every

suspicious case is examined with the cystoscope. In 1904 this firm

collected information from eighteen aniline factories which brought to

light thirty-eight cases, of which eighteen ended fatally. Seventeen were

operated on, and of these eleven were still alive although in three there

had been recurrence.

Tumours were found mostly in persons employed with aniline,

naphthylamine, and their homologues, but seven were in men employed with

benzidine.

Cases of benzene and toluidine poisoning in persons superintending tanks

and stills have been described.

Industrial paranitraniline poisoning has been described, and a fatal case

in the Höchst dye works was attributed by Lewin (as medical referee) to

inhalation of dust. Before his death the workman had been engaged for

five hours in hydro-extracting paranitraniline.

Paraphenylene diamine leads not unfrequently to industrial poisoning

from use of ursol as a dye. It produces skin eruptions and inflammation

of the mucous membrane of the respiratory passages.[12] No doubt the

intermediate body produced (diimine) acts as a powerful poison.

A case of metaphenylene diamine poisoning is quoted in the Report of the

Union of Chemical Industry for 1906. A worker had brought his coffee and

bread, contrary to the rules, into the workroom and hidden them under a

vessel containing the substance. Immediately after drinking his coffee he

was seized with poisoning symptoms, and died a few days later. Some of

the poison must have dropped into his coffee.

Few instances of poisoning from pure aniline colours are recorded.

At first all tar colours were looked upon as poisonous, but as they were

mostly triphenylmethane colours they would contain arsenious acid. When

the arsenic process was given up people fell into the other extreme

of regarding not only the triphenylmethane colours but all others as

non-poisonous, until experience showed that production and use of some of

the tar colours might affect the skin.

Finally, mention must be made of inflammation of the cornea caused by

methyl violet dust. The basic aniline dyes are said to damage the eye.

As opposed to this view is the fact that methyl violet and auramine are

used as anti-bactericidal agents, for treatment of malignant tumours, and

especially in ophthalmic practice.

II. SMELTING OF METALS

LEAD (ZINC, SILVER)

OCCURRENCE OF INDUSTRIAL LEAD POISONING IN GENERAL

_Chronic lead poisoning_ plays the most important rôle in industrial

metallic poisoning, and indeed in industrial poisoning generally. The

result everywhere where inquiry into industrial poisoning has been

instituted has been to place the number of cases of lead poisoning at

the top of the list; for one case of other forms of industrial poisoning

there are twenty of lead.

In the last few years a very extensive literature and one not easily

to be surveyed has grown up on the subject of chronic industrial lead

poisoning. I cannot attempt as I have done with other forms of poisoning

to do justice to all sources of literature on this subject.

As there is no obligation to notify industrial lead poisoning[B]—or

indeed any form of industrial poisoning—in many countries, the most

important source of information is wanting. Nevertheless more or less

comprehensive inquiries as to the extent of the disease in general have

been made in different countries and large cities which furnish valuable

data.

An idea of the yearly number of cases of lead poisoning occurring in

Prussia is given in the following statistics of cases treated in Prussian

hospitals for the years 1895-1901:

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

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

| 1895 | 1120 | 43 | 1163 |

| 1899 | 1601 | 23 | 1624 |

| 1900 | 1509 | 14 | 1523 |

| 1901 | 1359 | 24 | 1383 |

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

The occupation of these cases was as follows:

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

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

| 1895 | 364 | 312 | 347 |

| 1899 | 551 | 310 | 460 |

| 1900 | 516 | 360 | 378 |

| 1901 | 498 | 282 | 339 |

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

About half the cases, therefore, are caused by use of white lead. The

report of the sick insurance societies of the Berlin painters gives

information as to the proportion treated in hospital to those treated at

home, which was as 1:4.

The industries may be classified according to risk as follows[1]:

White lead workers, 33 per cent.; red lead workers, 32 per cent.; shot

and lead pipe workers, 20 per cent.; painters, 7-10 per cent.; lead and

zinc smelters, 8-9 per cent.; printers, 0·5 per cent.

In Austria through the Labour Statistical Bureau comprehensive

information is being collected as to the occurrence of lead poisoning in

the most dangerous trades, but is not yet published. The reports of the

factory inspectors give a very incomplete picture; for example, in 1905

only fifteen cases are referred to. In the most recent report (1909)

information of lead poisoning is only given for thirty works. Teleky

has made a general survey of the occurrence of lead poisoning from the

reports of the Austrian sick insurance societies.[2] From this we gather

that in Vienna, with an average membership of 200,000, there were, in

the five year period 1902-6, 634, 656, 765, 718, 772 cases of illness

involving incapacity from mineral poisons, which Teleky assumes were

practically all cases of lead poisoning. By circularising Austrian sick

insurance societies outside Vienna with a membership of about 400,000,

Teleky obtained information of 189 cases, which he considers too few.

In 1906-1908 inquiry was made by the sick insurance societies in Bohemia

as to the extent of lead poisoning. With an average number employed of

from 700,000 to 850,000 information was obtained of 91, 147, and 132

cases in the three years in question. The increase in 1907 was probably

accounted for by the greater attention paid to the subject.[3] The

number of ascertained cases of lead poisoning treated by the societies

of Hungary was 225 in 1901 and 161 in 1902. Teleky again considers these

figures too low, which is proved by Toth’s publications as to lead

poisoning in Hungarian lead smelting works, and especially Chyzer’s on

lead poisoning among Hungarian potters. Legge has reported fully in

the second International Congress for Industrial Diseases in Brussels

(September 1910) on occurrence of industrial lead poisoning in Great

Britain in the years 1900 to 1909. During that period 6762 cases with 245

deaths occurred. The number of cases in the course of the ten years had

diminished by 50 per cent. These figures appear remarkably small, but

it has to be borne in mind that the statistics referred to related only

to cases occurring in factories and workshops, and do not include cases

among house painters and plumbers. The number of such cases which came to

the knowledge of the Factory Department in 1909 was 241 (with 47 deaths)

and 239 in 1908 (with 44 deaths).

LEAD, SILVER, AND ZINC SMELTING

_Lead_ is obtained almost entirely from galena by three different

processes. In the _roast and reaction process_ galena is first roasted at

500°-600° C. and partially converted into lead oxide and lead sulphate:

on shutting off the air supply and increase of temperature the sulphur

of the undecomposed galena unites with the oxygen of the lead oxide

and sulphate to form sulphur dioxide, while the reduced metallic lead

is tapped. In the _roast and reduction_ process the ore is completely

calcined so as to get rid of sulphur, arsenic, and antimony. The oxides

(and sulphates) formed are reduced by means of coke in a blast furnace.

This process is generally applicable and is, therefore, that most in use.

The _precipitation_ process consists chiefly in melting galena with coke

and iron flux, whereby the lead is partly freed from the sulphur, and, in

addition to lead, iron sulphide is formed, which acts on the remaining

lead sulphide, producing a lead matte which can be further treated.

[Illustration: FIG. 27.—Smelting Furnace, showing mechanical charging

and exhaust ventilation applied to slag runs, &c. (_Locke, Lancaster &

W. W. & R. Johnson & Sons, Ltd. By permission of the Controller of H.M.

Stationery Office._)]

The roast and reaction process is carried out in specially constructed

reverberatory furnaces; small furnaces with small amounts of ore and at

as low a temperature as possible are the rule in the Kärntner process.

In the English process large amounts of ore are melted in large furnaces

at high temperatures so as to oxidise the material. The so-called

Tarnowitz process combines these two—large amounts of ore are roasted

in large furnaces at a moderate temperature. In the roast and reduction

process it depends on the nature of the ore whether the roasting is done

in reverberatory or blast furnaces. Generally the ore is in the form

of powder—less often in pieces. Pyritic ore (ore with much sulphur) is

almost always roasted in blast furnaces, and the sulphur dioxide evolved

can be used in the manufacture of sulphuric acid. Open-hearth furnaces

are rarely used now. Reverberatory furnaces are employed most frequently.

The lead thus obtained contains several other metals, especially silver,

copper, arsenic, antimony, iron, zinc, bismuth, and tin. Lead containing

silver (work-lead) is next _de-silverised_, after which follows refining

to get rid of the other impurities. For de-silverising work-lead rich

in silver (containing about 10 per cent.) _cupellation_ is practised,

in which the silver lead is melted and oxidised so that the lead is

converted into _litharge_, metallic silver remaining behind. In a

cupellation furnace the flame strikes on the top of the lead bath, and

at the same time air under slight pressure is driven in; the litharge

which forms is removed through suitable openings. The litharge that is

first formed contains silver and is treated again; the remainder is ready

for market. After the litharge has run off silver appears, containing

still 5-10 per cent. of lead, and it is again submitted to an analogous

refining process. Work-lead which does not contain enough silver to be

cupelled at once is generally treated first by either the Pattinson or

the Parkes’ process.

In the _Pattinson_ crystallising process work-lead is melted in open

semi-circular pots: as the pots cool crystals of lead poor in silver form

on the surface and are transferred by a perforated ladle into the next

pot: the silver collects in the small amount of molten lead remaining

behind. Lead that has become enriched by repeated crystallisation

contains a high percentage of silver and is cupelled. The _Parkes’_

process or _zinc de-silverisation_ depends on the formation of a

lead-zinc alloy which is less fusible than lead. Work-lead is melted

and agitated with addition of pure zinc. The crust which first rises on

cooling contains gold, copper, zinc, and lead, and is removed. Further

addition of zinc is then made: the rich silver crust which separates

is subsequently freed from lead by gradual heating in a reverberatory

furnace, and from zinc, in a zinc distilling retort. Other impurities

are got rid of by oxidising in reverberatory or other furnaces. Small

quantities of antimony and arsenic are removed by stirring with fresh

green sticks.

_Zinc_ is obtained principally from blende (sulphide of zinc) and from

calamine (carbonate of zinc). The process of zinc recovery depends on the

production of zinc oxide and reduction of this by carbon to metallic zinc.

Conversion of the ore to zinc oxide is effected by roasting. Since

the temperature at which reduction takes place is higher than the

melting-point of zinc the latter is volatilised (distilled) and must be

condensed in suitable condensers.

Calamine is calcined in a blast furnace. Blende was formerly roasted in

reverberatory furnaces, but such nuisance arose to the neighbourhood from

sulphur dioxide vapour that now Hasenclever-Helbig calcining furnaces

are used. These furnaces furnish a gas so rich in sulphur dioxide that

they serve at once for the production of sulphuric acid. The Hasenclever

furnaces consist of muffles placed one above another: the finely ground

ore is charged through hoppers above and then raked down from muffle to

muffle.

Reduction is carried out in the Belgian or Silesian process by strongly

heating calcined matte with coal in retorts. The zinc as it distils is

caught in special condensing receptacles (prolongs). After distillation

is complete the residue is raked out of the muffle and the furnace

charged afresh. As zinc ores generally contain much lead, the work-zinc

is therefore refined by remelting in a reverberatory furnace, during

which process the impurities collect on the zinc as dross and are removed

by agitation with sal-ammoniac or magnesium chloride.

[Illustration: FIG. 28.—Arrangement of Spelter Furnace showing

Ventilating Hood.]

RISK OF POISONING IN LEAD, SILVER, AND ZINC SMELTING.—As the description

of the manipulations in smelting processes shows, all involve risk of

lead poisoning. As a matter of fact in lead smelting much lead passes

into the atmosphere. In the smelting works at Tarnowitz yearly some

36,000 kilos of oxidised lead escape.

Estimations[4] of the amount of lead in air samples collected in lead

smelting works have been made. Thus in a cubic metre of air immediately

over the slag run from 0·0029 to 0·0056 g. of lead were found, so

that a worker in a ten-hour day would inhale from 0·013 to 0·025 g. of

lead. In a cubic metre of air immediately above the Parkes’ melting-pot

from 0·0056 to 0·0090 g. were found, so that a worker would inhale

daily from 0·0252 to 0·0405 g. if he kept constantly close to the pot.

On the handles of a de-silveriser 0·112 g. were found. In Hungarian

lead-smelting works the water in which the hands had been washed was

found to contain 1·27 g. of lead per litre. The hands of litharge

grinders and sifters showed the highest amounts.

Work carried on in lead-smelting works may be divided into five classes

according to risk. Those most exposed to risk are the smelters at lead

hearths and reverberatory furnaces, persons employed at the lead and

slag runs, flue cleaners, and in crushing and packing flake litharge.

Next come those employed at the refining furnaces, those breaking up the

roasted ore, blast furnace workers, and those employed at the cupellation

process. Attended with danger also is the removal of lead ashes and

distillation of the zinc crust. Less dangerous are transport of material,

crushing and mixing the ore, refining the work-lead and zinc crust, and

work at the Pattinson and Parkes’ processes.

In zinc smelting risk of lead poisoning is great, no matter which process

is in question, because of the high proportion of lead in the ore and

work-zinc. Swedish blende contains as much as 9 per cent. of lead, and

Upper Silesian 2½ per cent. or less. There is risk in calcination, but it

is much less than in the distillation process.[5]

There are no quite satisfactory statistics as to the number of cases

of lead poisoning in smelting works. Nevertheless, a number of recent

publications give valuable data for certain smelting works in Germany,

Austria, and Hungary.

From details[6] of lead poisoning at Tarnowitz it would appear that the

conditions have materially improved since 1884, the cases having declined

from 32·7 per 100 employed in 1884 to 6·2 in 1894 and 1895. The following

figures show the proportion affected in the different processes in the

years 1901 and 1902:

Process. Year. No. Employed. Cases. Per Cent.

Reverberatory Furnace { 1901 131 11 8·3

{ 1902 111 4 3·6

Blast Furnace { 1901 152 47 30·9

{ 1902 187 21 11·1

Cupelling Furnace { 1901 12 1 8·3

{ 1902 12 1 8·3

De-silverising { 1901 32 10 31·2

{ 1902 34 7 20·6

Other Employment { 1901 300 7 2·3

{ 1902 350 2 0·6

In one smelting works the percentage attack rate was 17·8 in 1901, and

27·1 in 1902. Here the number of workers had increased from 73 in 1901 to

129 in 1902, and the absolute and relative increase probably has relation

to the well-known fact that newly employed untrained workers become

affected. Similar incidence according to process can be given for the

Friedrich’s smelting works during the years 1903-1905:

Process. Year. No. Employed. Cases. Per Cent.

Reverberatory Furnace { 1903 86 12 13·9

{ 1904 87 8 9·2

{ 1905 83 11 13·3

Blast Furnace { 1903 267 59 22·1

{ 1904 232 24 10·3

{ 1905 247 27 10·9

De-silverising { 1903 56 12 21·4

{ 1904 73 4 5·5

{ 1905 75 4 5·3

Cupelling { 1903 16 4 25·0

{ 1904 15 1 6·7

{ 1905 14 1 7·1

Other Employment { 1903 330 5 1·5

{ 1904 309 4 1·3

{ 1905 347 7 2·0

Among 3028 cases of lead poisoning treated between 1853 and 1882 in

smelting works near Freiberg (Saxony) gastric symptoms were present in

1541, rheumatic pains in 215, cerebral symptoms in 144, paralysis in 58,

and lead colic in 426.

The recent reports of the German factory inspectors point still to rather

high incidence in many lead smelting works. Thus in the district of Aix

la Chapelle in 1909 there were sixty cases involving 1047 sick days, as

compared with 58 and 878 in 1908.

In a well-arranged smelting works near Wiesbaden fifty-two and forty-two

cases were reported in 1908 and 1909 respectively, among about 400

persons employed. This relatively high number was believed to be closely

connected with frequent change in the _personnel_. Introduction of the

Huntingdon-Heberlein method is thought to have exercised an unfavourable

influence.

Other smelting works in Germany appear to have a relatively small number

of reported cases. Thus in 1909 among 550 workers employed in four

smelting works in the Hildesheim district only four cases were reported,

and in the district of Potsdam among 600 smelters only five were found

affected on medical examination. There is no doubt that many of the cases

described as gastric catarrh are attributable to lead. Full information

as to the conditions in Austria is contained in the publication of the

Imperial Labour Statistical Bureau. In this comprehensive work the

conditions in smelting works are described. In the lead smelting works

at Przibram the cases had dropped from an average of 38·2 among the

4000-5000 persons employed to twenty-two in 1894 and to six in 1903, but

only the severer cases are included. No single case has occurred among

the 350-450 persons engaged in mining the ore, as galena (lead sulphide)

is practically non-poisonous. It was found, for example, that 50 per

cent. of the furnace men had (according to their statement) suffered from

lead colic. Of eight employed in the Pattinson process, seven stated they

had suffered from colic. The lead smelting works in Gailitz showed marked

frequency of lead poisoning—here the appointed surgeon attributed anæmia

and gastric and intestinal catarrh to lead:

Illness of Saturnine Origin.

Year. No. Lead Colic. Per Cent.

Employed. Anæmia. Intestinal Catarrh. due to

Gastric Total Lead Total Lead.

Catarrh. Sickness. Sickness.

1899 61 14 2 76 16 108 178 60·0

1900 57 6 2 16 5 29 80 36·2

1901 48 4 2 17 1 24 60 40·0

1902 47 — — 24 6 30 56 53·5

1903 49 — 3 11 4 18 57 31·6

The diminution in the number of cases, especially of colic, is

attributable to the efforts of the appointed surgeon.

At Selmeczbanya a diminution from 196 cases in 1899 (50·7 per cent.) to

six (2·2 per cent.) in 1905 had taken place. These figures point clearly

to the success of the hygienic measures adopted in the last few years.

In the large spelter works of Upper Silesia during the years 1896-1901,

among 3780 persons employed, there were eighty-three cases of lead colic

and paralysis, that is, about 2·2 per cent. each year. The following

tables show the incidence among spelter workers in the works in question

from 1902 to 1905:

ILLNESS AMONG ZINC SMELTERS

Lead Colic

Year. and Kidney Gastric Anæmia. Rheumatism. No.

Lead Paralysis. Disease. Catarrh. Employed.

1902 29 18 137 18 448 4417

1903 28 21 151 24 470 4578

1904 44 23 181 35 596 4677

1905 50 18 223 40 612 4789

Average 0·8% 0·5% 3·7% 0·6% 11·5% 4615

ILLNESS AMONG CALCINERS

Lead Colic

Year. and Kidney Gastric Anæmia. Rheumatism. No.

Lead Paralysis. Disease. Catarrh. Employed.

1902 — — 5 1 78 1149

1903 — — 9 — 112 1087

1904 2 — 68 1 136 1140

1905 1 2 47 2 134 1159

Average 0·08% 0·05% 2·6% 0·1% 10·2% 1134

In thirty-two spelter works in the district of Oppeln in the year 1905,

among 4789 spelter workers proper, there were 50 cases of colic, 18 of

kidney disease, 223 of gastric and intestinal catarrh, 40 of anæmia, and

612 of rheumatism, and among 1159 calciners 1 case of colic, 2 of kidney

disease, 47 of gastric catarrh, 2 of anæmia, and 134 of rheumatism. Cases

are much more numerous in spelter works where Swedish blende containing

lead is worked. It is remarkable, however, that in large spelter works in

Upper Silesia, where for years no cases of lead poisoning were reported,

medical examination showed that 20·5 per cent. had signs of lead

absorption.

White Lead and Lead Colours

MANUFACTURE.—The primitive Dutch process consisted in placing lead grids

in earthenware pots containing dilute acetic acid and covering them

with tan bark. Fermentation ensued with evolution of carbonic acid gas

and increase in temperature. The acetic acid vapour forms, with aid of

atmospheric oxygen, first basic lead acetate, which, by the action of

the carbonic acid gas, becomes converted into white lead and neutral

lead acetate. The product is crushed, sieved, and dried. In the German

or Austrian process thin sheets of metallic lead are hung saddle-wise

in chambers. Acetic acid vapour and carbonic acid gas (produced by

burning coke) are led in from below. The chamber is then sealed and kept

so for a considerable time. When the chamber is ‘ripe’ the white lead

that has formed is taken out, freed from uncorroded lead by spraying,

dried, finely ground, and packed. White lead comes on the market either

as a powder or incorporated with oil. Of the remaining lead colours,

red lead (Pb₃O₄) is much used. It is produced by heating lead oxide in

reverberatory furnaces with access of air and stirring.

Lead Poisoning in the Manufacture of White Lead and Lead Colours

The manufacture by the German process may be divided into three

categories according to the degree of risk run:

1. The most dangerous processes are hanging the plates in the chambers,

work at the filter press, drying, pulverising, and packing by hand.

2. Less dangerous are transport to the washer, washing, and grinding.

3. Relatively the least dangerous are casting the plates, transport of

them to the chambers, drying, mechanical packing, and mixing with oil.

The number of cases of lead poisoning in white lead factories is often

relatively great despite regulations. Casual labourers especially run

the greatest risk. This is frequently brought out in the reports of the

German factory inspectors, who connect the high proportion of cases

directly with the large number of unskilled workers. Regulations are

really only successful in factories with regular employment.

This has been found also in Great Britain, where the Medical Inspector

of Factories showed that the cases among regular workers numbered 6 per

cent. and among casual workers 39 per cent.

The following table gives particulars as to the occurrence of lead

poisoning in the white lead factories in the district of Cologne in 1904,

some of which have admirable hygienic arrangements:

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

| | +-----------------+---------------+ No. of |

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

|Cologne I. | White lead {| 46 | 59 | 32 | 9 | 16 | 25 | 16 |

| | {| 173 | 95 | 127 | 13 | 17 | 30 | 22 |

| ” I. | Litharge and{| 46 | 4 | 38 | 5 | 1 | 6 | 7 |

| | red lead {| 76 | 62 | 49 | 3 | 4 | 7 | 15 |

| | Chromate {| 14 | 2 | 11 | — | — | — | 5 |

| | {| 43 | 72 | 33 | — | — | — | 7 |

|Cologne II.| White lead, {| | | | | | | |

| | litharge, {| 107 | 332 | 91 | 6 | 34 | 40 | 30 |

| | and red lead{| 102 | 332 | 76 | 9 | 19 | 28 | 38 |

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

It is worth noting that cases of lead poisoning have been reported in the

manufacture of zinc white, as, for example, in Bohemia in 1907 and 1908.

USE OF LEAD COLOURS AND PAINTS (HOUSE PAINTERS, DECORATORS, ETC.)

Use of lead colours, especially by painters and decorators, causes

relatively much lead poisoning. Apart from ignorance of danger on

the part of the worker, and lack of personal cleanliness, unsuitable

methods of working add to the danger, especially dry rubbing of painted

surfaces, which gives rise to much dust containing lead. Again, the

crushing and mixing of lumps of white lead and rubbing lead colours with

the hand are very dangerous.

The following German and Austrian figures enable conclusions to be

drawn as to the frequency of lead poisoning among painters. In the sick

insurance societies of Frankfurt-a-M. in 1903 of every 100 painters 11·6

suffered from an attack of lead poisoning. The similar sick insurance

society of painters in Berlin has kept useful statistics which are given

in the following table for the ten years 1900-9:

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

| | | No. | |

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

| 1900 | 3889 | 357 | 9·18 |

| 1901 | 3616 | 335 | 9·26 |

| 1902 | 3815 | 308 | 8·07 |

| 1903 | 4397 | 470 | 10·69 |

| 1904 | 5029 | 516 | 10·26 |

| 1905 | 5328 | 471 | 8·84 |

| 1906 | 5355 | 347 | 6·48 |

| 1907 | 5173 | 379 | 7·32 |

| 1908 | 4992 | 298 | 5·97 |

| 1909 | 4781 | 285 | 5·96 |

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

|Average | 4637 | 376·6 | 8·11 |

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

This shows that lead poisoning among the painters of Berlin is happily

diminishing, which may be attributed to recent regulations. The society,

however, complains in its reports that not all cases of lead appear

as such in their statistics, and believes that all diseases entered

as rheumatism, gastric catarrh, nervous complaints, heart and kidney

disease, should be regarded as associated with lead. The kinds of work in

which painters suffer most are painting iron girders and machines, sheet

metal and iron furniture, railway waggons, agricultural implements, coach

painting, cabinet-making, shipbuilding, and the use of red and white

lead. The use of lead colours, _lead acetate_, and _lead chromate_ often

give rise to lead poisoning. Colours containing lead are not infrequently

used in the textile industry in dyeing, printing, and finishing. White

lead has been used for weighting the weft.

Teleky has described cases of lead poisoning in which _silk thread_ was

weighted with acetate of lead. As a consequence a number of women engaged

in sewing on fringes with the thread suffered. The English factory

inspectors’ reports describe cases from manipulating _yarn dyed with

chromate of lead_.[7]

_Chromate of lead_ and _white lead_ are used in colouring oil-cloth,

artificial flowers, paper, rubber goods, pencils, penholders, socks,

sealing-wax, candles, and stamps.

USE OF LEAD IN THE CHEMICAL INDUSTRY

Lead poisoning has been frequently observed in such branches of the

chemical industry as require large leaden or lead-lined vessels and

pipes: the persons affected are principally those engaged in lead burning.

Risk is considerable in manufacture of lead acetate. The most dangerous

processes are drying and packing the crystals.

MANUFACTURE OF ELECTRIC ACCUMULATORS

The manufacture of accumulators begins with the casting of lead plates,

which are then polished and dressed. Next follows ‘pasting,’ that is,

smearing the negative plate with a paste of litharge, the positive plate

being ‘formed’ by having an electric current passed through so that the

lead is converted into spongy peroxide. The wooden boxes in which the

plates are assembled are lead-lined.

The most dangerous processes are casting, wire-brushing, and pasting—the

latter especially when done by hand.

In the years 1908 and 1909 among about 761 workers employed in the

accumulator factories of Cologne there were fifty-six cases of lead colic

and seventy-nine of gastric and intestinal catarrh. Further figures

for German accumulator works show that in the two largest accumulator

factories in the district of Potsdam employing 142 workers there were

fifteen cases in 1904. In Great Britain, in the ten years 1900-1909, 285

cases were reported—an average of about thirty a year.

THE CERAMIC INDUSTRY

Risk is present in several branches of the ceramic industry. It is

greatest in glazing earthenware, but not infrequent also in the porcelain

and glass industries. It is impossible to deal with the extensive

literature on this subject exhaustively. A comprehensive and detailed

survey of lead poisoning in the ceramic industry on the Continent is

that by Kaup. Distinction is made between leadless glazes which melt

at high temperature and lead glazes which have the advantage of a low

melting-point. Galena and litharge are used in the preparation of glazes

for common earthenware and red and white lead for ware of better quality.

Distinction has to be made between a lead silicious glaze for pottery

ware, a lead and boric acid glaze for stoneware, and a lead and zinc

oxide glaze for ordinary faience and stoneware. Seegar, the celebrated

expert, praises the advantage of lead glaze and the use of lead in the

ceramic industry—it is indeed practically indispensable—and speaks of the

poisonous nature of lead as its only fault. The components of the glaze

must have definite relation to the hardness or softness of the body. The

higher the proportion of silicic acid in the glaze the harder the firing

it will stand; the more the flux materials are in excess the lower will

the melting point be.

The most important flux materials are, arranged in order of decreasing

fusibility, lead oxide, baryta, potash, soda, zinc oxide, chalk,

magnesia, and clay.

The _glaze_ is made by first mixing the ingredients dry, and then

either fritting them by fluxing in a reverberatory furnace and finally

grinding them very finely in water or using the raw material direct. In

the fritting process in the case of the lead glazes the soluble lead

compounds become converted into less soluble lead silicates and double

silicates.

The glaze is applied in different ways—dipping, pouring, dusting,

blowing, and volatilising. Air-dried and biscuited objects are dipped;

pouring the glaze on is practised in coarse ware, roofing-tiles, &c.;

dusting (with dry finely ground glaze, litharge, or red lead) also in

common ware; glaze-blowing (aerographing) and glaze dusting on porcelain.

In these processes machines can be used. Bricks are only occasionally

glazed with glazes of felspar, kaolin, and quartz, to which lead oxide

is often added in very large quantity. Lead poisoning in _brick works_

in view of the infrequent use of lead is not common, but when lead is

used cases are frequent. Kaup quotes several cases from the factory

inspectors’ reports: thus in three roof-tiling works examination by the

district physician showed that almost all the workers were affected.

_Coarse ware pottery_ is made of pervious non-transparent clay with

earthy fracture—only a portion of this class of ware (stoneware) is

made of raw materials which fire white. Such ware generally receives a

colourless glaze. The clay is shaped on the potter’s wheel, and is then

fired once or, in the better qualities, twice.

Grinding the ingredients of the glaze is still often done in primitive

fashion in mortars. The glaze is usually composed of lead oxide and

sand, often with addition of other lead compounds as, for example, in

quite common ware, of equal parts of litharge, clay, and coarse sand.

Sometimes, instead of litharge, galena (lead sulphide) or, with better

qualities of ware, red lead or ‘lead ashes’ are used.

The grinding of the glazes in open mills or even in mortars constitutes a

great danger which can be prevented almost entirely by grinding in ball

mills. The glaze material is next mixed with water, and the articles are

either dipped into the creamy mass or this is poured over them. In doing

this the hands, clothes, and floors are splashed. The more dangerous

dusting-on of glaze is rarely practised. Occasionally mechanical

appliances take the place of hand dipping. Placing the ware in the glost

oven is done without placing it first in saggars.

In the better qualities of pottery cooking utensils, which are fired

twice, a less fusible fritted lead glaze is generally used. Coloured

glaze contains, besides the colouring metallic oxides, 30-40 per cent. of

litharge or red lead.

As Kaup shows, Continental factory inspectors’ reports make only isolated

references to occurrence of lead poisoning in potteries. Insight into the

conditions in small potteries is obtained only from the Bavarian reports.

In Upper Bavaria ninety-three potteries employ 157 persons who come into

contact with lead glaze. Eleven cases were known to have occurred in the

last four years. Teleky found thirty-six cases of lead poisoning (mostly

among glostplacers) in the records of the Potters’ Sick Insurance Society

of Vienna.

Chyzer has described the striking conditions in Hungary. There there

are about 4000 potters, of whom 500 come into contact with lead glaze.

Chronic lead poisoning is rife among those carrying on the occupation as

a home industry. Members of the family contract the disease from the dust

in the living rooms. This dust was found to contain from 0·5 to 8·7 per

cent. of lead.

In the china and earthenware factories in Great Britain, in the ten years

1900-9, 1065 cases with fifty-seven deaths were reported.

_Manufacture of stove tiles._—The application of glaze to stove tiles is

done in different ways. The two most important kinds are (1) fired tiles

and (2) slipped tiles. In the production of fired tiles a lead-tin alloy

consisting of 100 parts lead and 30-36 parts tin—so-called ‘calcine’—are

melted together in fireclay reverberatory or muffle furnaces and raked

about when at a dull red heat so as to effect complete oxidation. The

material when cool is mixed with the same quantity of sand and some

salt, melted in the frit kiln, subsequently crushed, ground, mixed with

water, and applied to the previously fired tiles. In this process risk

is considerable. Presence of lead in the air has been demonstrated even

in well-appointed ‘calcine’ rooms. In unsuitably arranged rooms it was

estimated that in a twelve-hour day a worker would inhale 0·6 gramme of

lead oxide and that 3-8 grammes would collect on the clothes.

_Slipped tiles_ are made in Meissen, Silesia, Bavaria, and Austria by

first applying to them a mixture of clay and china clay. The glaze

applied is very rich in lead, containing 50-60 parts of red lead or

litharge. Generally the glaze is applied direct to the unfired tiles

and fired once. Figures as to occurrence of poisoning in Germany are

quoted by Kaup from the towns of Velten and Meissen. Among from 1748 to

2500 persons employed thirty-four cases were reported in the five years

1901-5. Thirteen cases were reported as occurring in the three largest

factories in Meissen in 1906.

From other districts similar occurrence of poisoning is reported. In

Bohemia in a single factory in 1906 there were fourteen cases with one

death, in another in 1907 there were fourteen, and in 1908 twelve cases;

eight further cases occurred among majolica painters in 1908.

_Stoneware and porcelain._—Hard stoneware on a base of clay, limestone,

and felspar has usually a transparent lead glaze of double earth

silicates of lead and alkalis, with generally boric acid to lower the

fusing-point; the lead is nearly always added in the form of red lead

or litharge. The portion of the glaze soluble in water is fritted, and

forms, when mixed with the insoluble portion, the glaze ready for use.

The frit according to Kaup contains from 16 to 18 per cent. of red lead,

and the added material (the mill mixing) 8-26 parts of white lead; the

glaze contains from 13 to 28 parts of lead oxide. The ware is dipped or

the glaze is sometimes aerographed on. Ware-cleaning by hand (smoothing

or levelling the surface with brushes, knives, &c.) is very dangerous

work unless carried out under an efficient exhaust. Colouring the body

itself is done with coloured metal oxides or by applying clay (slipping)

or by the direct application of colours either under or over the glaze.

Some of the under-glaze colours (by addition of chrome yellow or nitrate

of lead or red lead) contain lead and are applied with the brush or

aerograph or in the form of transfers.

_Plain earthenware_ is either not glazed or salt glazed; only when

decorated does it sometimes receive an acid lead glaze.

_Porcelain_ receives a leadless glaze of difficultly fusible silicate

(quartz sand, china clay, felspar). Risk is here confined to painting

with lead fluxes (enamel colours) containing lead. These fluxes are

readily fusible glasses made of silicic acid, boric acid, lead oxide, and

alkalis, and contain much lead (60-80 per cent. of red lead).

In the _glass industry_ lead poisoning may occur from use of red lead as

one of the essential ingredients. In Great Britain, in the years 1900-9,

forty-eight cases were reported in glass polishing from use of putty

powder.

LETTERPRESS PRINTING, ETC.

Type metal consists of about 67 per cent. lead, 27 per cent. antimony,

and 6 per cent. tin, but sometimes of 75 per cent. lead, 23 per cent.

antimony, and 2 per cent. tin.

The actual printer comes least of all in contact with lead. Use of lead

colours (white lead, chromate of lead, &c.) may be a source of danger,

especially in the preparation of printing inks from them and in cleaning

the printing rolls. A further, if slight, danger arises from the use of

bronze powder consisting of copper, zinc, and tin. The two last-named

metals contain from 0·1 to 0·5 per cent. of lead, and in the application

and brushing off of the bronze there is a slight risk.

The compositor is exposed to constant danger from handling the type and

disturbing the dust in the cases. This dust may contain from 15 to 38

per cent. of lead. Blowing the dust out of the cases with bellows is

especially dangerous, and want of cleanliness (eating and smoking in the

workroom) contributes to the risk.

Type founders and persons engaged in rubbing and preparing the type

suffer. Introduction of type-casting machines (linotype, monotype) has

lessened the danger considerably.

No lead fumes are developed, as a temperature sufficiently high to

produce them is never reached. In all the processes, therefore, it is

lead dust which has to be considered.

The following figures of the Imperial Statistical Office as to occurrence

of lead poisoning among printers in Vienna indicate the relative danger:

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

| |1901-1906. |1901-1906. |1901-1906.|

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

|Compositors | 3182 | 90·3 | 2·8 |

|Printers | 809 | 20·3 | 2·4 |

|Casters and Stereotypers | 241 | 15·8 | 6·6 |

|Females employed in casting| 74 | 8·17 | 10·8 |

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

In Bohemia there is reference to thirty-eight cases in letterpress

printing in 1907 and twenty-seven in 1908.

Among 5693 persons treated for lead poisoning between the years 1898 and

1901 in hospitals in Prussia, 222 were letterpress printers.

Between 1900 and 1909 in Great Britain 200 cases of lead poisoning were

reported.

VARIOUS BRANCHES OF INDUSTRY

The number of industries using lead is very large. Layet as long ago as

1876 enumerated 111. We, however, limit ourselves to those in which the

risk is considerable.

Use of _lead beds_ in _file-cutting_ has given rise to many cases.

Further, to harden the file it is dipped into a bath of molten lead.

From 3 to 6 per cent. of lead has been found in the dust in rooms where

hardening is done.

Of 7000 persons employed in file-cutting in the German Empire in the

years 1901-5 on an average 30·5 or 0·43 per cent. were affected yearly.

In Great Britain 211 cases were reported in the years 1900-9.

In _polishing precious stones_ formerly many cases of lead poisoning

occurred, the reason being that the polishers come into contact with

particles of lead and fix the diamonds to be polished in a vice composed

of an alloy of lead and tin. Danger is increased when the stones are

actually polished on revolving leaden discs. In Bohemia granite polishing

used to be done in this way, but is now replaced in many factories by

carborundum (silicon carbide).

Musical instrument making in Bohemia in the years 1906-8 was found

regularly to give rise to cases of lead poisoning from use of molten lead

in filling them with a view to shaping and bending. In lead pipe and

organ pipe works, lead burning, plumbing, &c., considerable risk is run.

Often the causes of lead poisoning are difficult to discover, and, when

found, surprising. Thus shoemakers have suffered from holding leaden

nails in the mouth. Again, cases in women have been reported from cutting

out artificial flowers or paper articles with aid of lead patterns, or

counting stamps printed in lead colours.[8]

MERCURY

As metallic mercury gives off vapour even at ordinary temperatures,

poisoning can occur not only in the recovery of the metal from the ore,

but also in all processes in which it is used.

Chronic industrial poisoning occurs principally in the preparation and

use of mercury salts, in recovery of the metal itself and of other metals

with use of an amalgam, in water gilding, from use of nitrate of mercury

in the preparation of rabbit fur for felt hat making, from use of mercury

pumps in producing the vacuum in electric filament lamps, and in making

barometers and thermometers.

PREPARATION.—Mercury is obtained by roasting cinnabar (sulphide of

mercury). When cinnabar is heated with access of air the sulphide burns

to sulphur dioxide and the mercury volatilises and is subsequently

condensed. Formerly the process was carried on in open hearths; now it

is done usually in blast furnaces. The mercury is condensed in Idria

in large chambers cooled with water, while at Almaden in Spain it is

collected in a series of small earthenware receptacles (aludels), from

small openings in which the mercury flows in gutters and collects. The

mercury so recovered is usually redistilled.

On the walls of the condensers a deposit of sulphide and oxide of mercury

collects, removal of which is one of the operations most attended with

risk.

Recovery of silver or gold by amalgamation with mercury is carried on

only in America. The metallic silver or gold is taken up by the mercury,

from which it is recovered by distillation.

The conditions in the quicksilver mines of Idria in Austria have improved

of late years. Thus in the five years prior to 1886 of 500 cases of

illness more than 11 per cent. were due to chronic mercurial poisoning.

In 1906, 209 persons were employed, of whom only one-third were permanent

hands. Among these the sickness rate was very high (95-104 per cent.).

Of 741 cases of illness among the miners there were six of mercury

poisoning, and of 179 among persons employed in recovery of the metal,

twelve cases.[1]

The conditions of employment in the cinnabar mines of Monte Amiata in

Italy have recently been described in detail.[2] Here, although the

recovery of the metal is carried out in modern furnaces, thus greatly

reducing the danger, nevertheless nearly all the furnace workers suffer

from chronic poisoning.

In _silvering of mirrors_ the leaf of tinfoil was spread out on an

inclined table; mercury was poured over it and the sheet of glass laid

on the top with weights. The superfluous mercury was squeezed out and

ran away owing to the sloping position of the table. Now this process,

even in Fürth, is almost entirely replaced by the nitrate of silver and

ammonia process. Years ago the number of cases of poisoning was very

serious in places where, as in Fürth, the work was carried on as a home

industry.

In the production of _incandescent electric bulbs_ danger arises from

breaking of the glass pipes of the pumps and scattering of mercury on

the floor of the workrooms. Since there is a growing tendency to replace

mercury pumps by air pumps such cases ought to become rare.

In _water gilding_—a process little employed now—the metal objects

(military buttons, &c.) to be gilded, after treatment with a flux, are

brushed over with the mercury amalgam, and subsequently fired to drive

off the mercury. Unless careful provision is made to carry away the

vapour chronic poisoning cannot fail to occur. Even sweeps have been

affected after cleaning the chimneys of water gilders’ workshops. In

Great Britain, between 1899 and 1905, six cases were reported among water

gilders.

In the _manufacture of barometers_ and thermometers mercury poisoning is

not infrequent. Between 1899 and 1905 sixteen such cases were reported in

England; during the same period there were seventeen cases among those

putting together electrical meters.

Risk of mercurial poisoning is constantly present in _hatters’ furriers’

processes_ and in subsequent processes in felt hat factories. The risk

from use of nitrate of mercury is considerable to those brushing the

rabbit skins with the solution (carotting), and subsequently drying,

brushing, cutting, locking, and packing them. According to Hencke in

100 kilos of the carotting liquid there are 20 kilos of mercury. In

England, in the years 1899-1905, thirteen cases of mercurial poisoning

were reported in hatters’ furriers’ processes. Among eighty-one persons

so employed the medical inspector found twenty-seven with very defective

teeth as the result of the employment, and seventeen with marked tremor.

In the _manufacture of mercurial salts_ poisoning occurs chiefly when

they are made by sublimation, as in the manufacture of vermilion, of

corrosive sublimate (when mercurous sulphate is sublimed with salt), and

in the preparation of calomel (when sublimate ground with mercury or

mercurous sulphate mixed with mercury and salt is sublimed). Between 1899

and 1905 in England seven cases were reported from chemical works. As

to occurrence of mercury poisoning from _fulminate of mercury_, see the

chapter on Explosives.

ARSENIC

Chronic industrial _arsenical poisoning_, both as to origin and course,

is markedly different from the acute form.

The chronic form arises mainly from inhalation of minute quantities of

metallic arsenic or its compounds in recovery from the ore, or from the

use of arsenic compounds in the manufacture of colours, in tanyards, and

in glass making. Acute industrial _arseniuretted hydrogen poisoning_ is

especially likely to occur where metals and acids react on one another

and either the metal or the acid contains arsenic in appreciable amount.

Further, arseniuretted hydrogen may be contained in gases given off in

smelting operations and in chemical processes.

RECOVERY OF ARSENIC AND WHITE ARSENIC.—Pure arsenic is obtained from

native cobalt and arsenical pyrites by volatilisation on roasting the

ore in the absence of air. After the furnace has been charged sheet iron

condensing tubes are affixed to the mouths of the retorts, which project

out of the furnace, and to these again iron or earthenware prolongs.

Arsenic condenses on the sides of the sheet metal tubes and amorphous

arsenic, oxides, and sulphides in the prolongs. After sublimation has

been completed the contents of the prolongs are removed and used for

production of other arsenic compounds; the (generally) argentiferous

residues in the retorts are removed and further treated in silver

smelting works; finally, the crusts of crystalline arsenic (artificial

fly powder) are knocked out from the carefully unrolled sheet iron tubes.

As can be readily understood from the description opportunity of

poisoning from volatilisation of arsenic and of arsenic compounds is

considerable. Metallic arsenic is used for making hard shot, and for

increasing the brilliancy and hardness of metal alloys (type metal, &c.).

_White arsenic_ (arsenic trioxide) is obtained by roasting with access of

air in reverberatory furnaces arsenical ores and smelting residues. The

vapours of white arsenic sublime and are condensed as a powder in long

walled channels or in chambers, and are resublimed in iron cylinders.

White arsenic is used in making colours, in glass (for decolourising

purposes), as an insecticide in the stuffing of animals, &c.

INDUSTRIAL ARSENIC POISONING.—In the _extraction of arsenic_ and

preparation of arsenious acid danger is present. But reliable accounts in

literature of poisoning among those engaged in arsenic works are wanting.

Those engaged in roasting operations and packing suffer much from skin

affections. Similar poisoning is reported in the smelting of other

arsenical ores—nickel, cobalt, lead, copper, iron, and silver, from

arsenic compounds present in the fumes. This is especially the case in

the smelting of tin, which generally contains arsenical pyrites.

Danger is present also in _unhairing_ (i.e. removing the wool from sheep

skins), since the skins imported from Buenos Aires and Monte Video are

treated with a preservative which, in addition to sodium nitrate, soda,

and potash, contains generally arsenious acid.

In _tanneries_ a mixture of arsenic sulphide (realgar) and lime is used

for unhairing. Arsenic is used also for preserving and stuffing animal

furs; but although affections of the skin are described I cannot find

reference to arsenical poisoning.

The inspector for East London in 1905 refers to severe eczematous

eruptions on face, neck, and hands, affecting workers in a _sheep dip_

works—mainly in the packing of the light powder in packets.

Formerly the use of arsenic in the manufacture of colours was great,

especially of _emerald (Schweinfurter) green_. This is made by dissolving

arsenious acid in potash with addition of acetate of copper. Drying and

grinding the material constitute the main danger. Scheele’s green is

another arsenical colour.

Use of _arsenic colours_ is becoming less and less. But in colour

printing of paper and colouring of chalk they are still employed. They

are used, too, as mordants in dyeing, but cases of poisoning from these

sources in recent years are not to be found.

The dust in many glass works contains, it is stated, as much as 1·5 per

cent of white arsenic.

Despite the numerous opportunities for arsenical poisoning in industries

it is rare or, at any rate, is only rarely reported.

ARSENIURETTED HYDROGEN POISONING.—Industrial poisoning from arseniuretted

hydrogen is caused mostly by inhalation of the gases developed by the

action on one another of acids and metals which contain arsenic. Hydrogen

gas as usually prepared for filling balloons gives occasion for poisoning.

In Breslau in 1902 five workmen became affected, of whom three died from

inhalation of arseniuretted hydrogen gas in filling toy balloons.[1]

Further, use of hydrogen in lead burning may expose to risk, and also

preparation of zinc chloride flux.

Of thirty-nine recorded cases of arseniuretted hydrogen poisoning twelve

were chemists, eleven workers filling toy balloons, seven aniline

workers, five lead smelters, three balloonists, and in one the origin

could not be traced. Nineteen of these proved fatal within from three to

twenty-four days.[2]

Cases are recorded (1) in the reduction of nitroso-methylaniline with

zinc and hydrochloric acid; (2) in the preparation of zinc chloride from

zinc ashes and hydrochloric acid; (3) from manufacture of zinc sulphate

from crude sulphuric acid and zinc dust; (4) in spelter works in the

refining of silver from the zinc crust with impure hydrochloric acid; and

(5) in the formation room of accumulator factories.

The English factory inspectors’ report describes in 1906 occurrence

of three cases in an electrolytic process for the recovery of copper

in which the copper dissolved in sulphuric acid was deposited at the

cathode, and hydrogen at the lead anode. In the 1907 report mention is

made of two cases, one affecting a chemist separating bismuth from a

solution of bismuth chloride in hydrochloric acid, and the other (which

proved fatal) a man who had cleaned a vitriol tank.

The poisoning resulting from ferro-silicon is in part referable to

development of arseniuretted hydrogen gas.

ANTIMONY

It seems doubtful if industrial poisoning can really be traced to

antimony or its compounds; generally the arsenic present with the

antimony is at fault. Erben[1] considers that industrial antimony

poisoning occurs among workmen employed in smelting antimony alloys in

making tartar emetic through inhalation of fumes of oxide of antimony.

A case is cited of a workman in Hamburg engaged in pulverising pure

antimony who was attacked with vomiting which lasted for several days,

and the inspector of factories noted epistaxis (nose bleeding) and

vomiting as following on the crushing of antimony ore.

Compositors in addition to chronic lead poisoning may suffer, it is

alleged, from chronic antimony poisoning, showing itself in diminution

in the number of white blood corpuscles and marked eosinophilia. These

changes in the blood could be brought about experimentally in rabbits.

Antimony was found by the Marsh test in the stools of those affected.

IRON

_Pig iron_ is obtained by smelting iron ores in blast furnaces (fig. 29),

through the upper opening of which charges of ore, limestone or similar

material to act as a flux, and coke are fed in succession. The furnaces

are worked continuously, using a blast of heated air; carbon monoxide is

produced and effects the reduction of the ore to molten iron. The latter

accumulates in the hearth and is covered with molten slag; this flows

constantly away through an opening and is collected in slag bogies for

removal, or is sometimes cooled in water.

The crude iron is tapped from time to time, and is led in a fluid

condition into moulds called ‘pigs,’ in which it solidifies. Cast iron is

occasionally used direct from the blast furnace for the purpose of making

rough castings, but generally it is further refined before being used in

a foundry by remelting with cast iron scrap in a cupola furnace.

[Illustration: FIG. 29.

_a_ Hearth; _b_ Bosh; _c_ Shaft; _d_ Gas uptake; _e_ Down-comer; _f_

Tuyères with water cooling arrangement; _g_ Blast pipes; _h_ Tapping

hole; _k_ Supporting columns; _l_ Furnace bottom; _m_ Charging hopper;

_n_ Bell with raising and lowering arrangement.]

_Wrought iron_ is made by treating pig iron in refinery and puddling

furnaces; in these much of the carbon is removed as carbon monoxide, and

from the puddling furnace the iron is obtained as a pasty mass which can

be worked into bars, rods, or plates.

_Steel_ is made in various ways. The Acid Bessemer process consists in

forcing compressed air in numerous small streams through molten cast

iron, in iron vessels (converters) which are lined with ganister, a

silicious sandstone. These can be rotated on trunnions. Basic Bessemer

steel is made in similar converters by the Thomas-Gilchrist or basic

process, which can be applied to pig irons containing phosphorus. The

latter is removed by giving the converter a basic lining of calcined

magnesium limestone mixed with tar.

In the _Martin_ process steel is obtained by melting together pig iron

with steel scrap, wrought iron scrap, &c., on the hearth of a Siemens

regenerative furnace with a silicious lining.

In iron smelting the most important danger is from _blast furnace

gas_ rich in carbonic oxide. Sulphur dioxide, hydrocyanic acid, and

arseniuretted hydrogen gas may possibly be present.

When work was carried out in blast furnaces with open tops the workers

engaged in charging ran considerable risk. But as the blast furnace gas

is rich in carbonic oxide and has high heating capacity these gases

are now always led off and utilised; the charging point is closed by a

cup (Parry’s cup and cone charger) and only opened from time to time

mechanically, when the workers retire so far from the opening as to be

unaffected by the escaping gas. The gas is led away (fig. 29) through a

side opening into special gas mains, is subjected to a purifying process

in order to rid it of flue dust, and then used to heat the blast, fire

the boilers, or drive gas engines.

Severe blast furnace gas poisoning, however, does occur in entering the

mains for cleaning purposes. Numerous cases of the kind are quoted in the

section on Carbonic oxide poisoning.

The gases evolved on tapping and slag running can also act injuriously,

and unpleasant emanations be given off in granulating the slag (by

receiving the fluid slag in water).

In the puddling process much carbonic oxide is present. Other processes,

however, can scarcely give rise to poisoning.

The _basic slag_ produced in the Thomas-Gilchrist process is a valuable

manure on account of the phosphorus it contains; it is ground in

edge runners, and then reduced to a very fine dust in mills and

disintegrators. This dust has a corrosive action already referred to in

the chapter on Phosphorus and Artificial Manures.

The poisoning caused by _ferro-silicon_ is of interest. Iron with high

proportion of silicon has been made in recent years on a large scale

for production of steel. Some 4000 tons of ferro-silicon are annually

exported to Great Britain from France and Germany. It is made by

melting together iron ore, quartz, coke, and lime (as flux) at very

high temperature in electrical furnaces. The coke reduces the quartz

and ore to silicon and metal with the production of ferro-silicon.

Certain grades, namely those with about 50 per cent. silicon, have

the property of decomposing or disintegrating into powder on exposure

for any length of time to the air, with production of very poisonous

gases containing phosphoretted and arseniuretted hydrogen. The iron and

quartz often contain phosphates, which in presence of carbon and at the

high temperature of the electrical furnace would no doubt be converted

into phosphides combining with the lime to form calcium phosphide;

similarly any arsenic present would yield calcium arsenide. These

would be decomposed in presence of water and evolve phosphoretted and

arseniuretted hydrogen gas. In addition to its poisonous properties it

has also given rise to explosions.

[In January 1905 fifty steerage passengers were made seriously ill and

eleven of them died. In 1907 five passengers died on a Swedish steamer

as the result of poisonous gases given off from ferro-silicon, and

more recently five lives were lost on the steamer _Aston_ carrying

the material from Antwerp to Grimsby.[C] This accident led to full

investigation of the subject by Dr. Copeman, F.R.S., one of the Medical

Inspectors of the Local Government Board, Mr. S. R. Bennett, one of H.M.

Inspectors of Factories, and Dr. Wilson Hake, Ph.D., F.I.C., in which the

conclusions arrived at are summarised as follows:

1. Numerous accidents, fatal and otherwise, have been caused

within the last few years by the escape of poisonous and

explosive gases from consignments of ferro-silicon, which,

in every instance, have been found to consist of so-called

high-grade ferro-silicon, produced in the electric furnace.

2. These accidents, for the most part, have occurred during

transport of the ferro-silicon by water, whether in sea-going

vessels or in barges and canal-boats plying on inland waters.

3. These accidents have occurred in various countries and on

vessels of different nationalities, while the ferro-silicon

carried has, in almost every instance, been the product of a

different manufactory.

4. Ferro-silicon, especially of grades containing from 40 per

cent. to 60 per cent. of silicon, is invariably found to evolve

considerable quantities of phosphoretted hydrogen gas, and, in

less amount, of arseniuretted hydrogen, both of which are of a

highly poisonous nature. A certain amount of the gas evolved

is present, as such, in the alloy, being ‘occluded’ in minute

spaces with which its substance is often permeated.

5. As the result of careful investigation, it has been

shown that certain grades of ferro-silicon—notably such as

contain about 33 per cent., 50 per cent., and 60 per cent. of

silicon—even when manufactured from fairly pure constituents,

are both brittle and liable to disintegrate spontaneously, this

latter characteristic being apt to be specially marked in the

case of the 50 per cent. grade.

All these grades are commonly employed at the present time.

6. In the event of disintegration occurring, the amount of

surface exposed will, obviously, be greater than if the mass

were solid.

7. Evolution of poisonous gases is greatly increased by the

action of moisture, or of moist air, under the influence

of which phosphoretted hydrogen is generated from calcium

phosphide, which, in turn, is formed, in large part, at any

rate, from the calcium phosphate present in anthracite and

quartz, at the high temperature of the electric furnace. If

spontaneous disintegration of the alloy also occurs, much

larger quantities of gas would be given off from such friable

and unstable material, other conditions being equal. The

greater or less tendency of a given sample to evolve poisonous

gases, and even a rough estimate of their probable amount may

be arrived at by the use of test-papers prepared with silver

nitrate.

8. There is no evidence that low-grade ferro-silicon (10 to

15 per cent.), produced in the blast-furnace, has ever given

rise to accidents of similar character to those known to have

been caused by the high-grade electrically produced alloy.

Blast-furnace ferro-silicon does not evolve poisonous gases

even in presence of moisture.

9. As regards ferro-silicon produced in the electric furnace,

the evidence available goes to show that certain percentage

grades are practically quite innocuous. This statement applies

to grades of alloy of a silicon content up to and including

30 per cent., and probably also, though in considerably less

degree, to those of 70 per cent. and over.

10. In view of the fact that the use of ferro-silicon of grades

ranging between 30 per cent. and 70 per cent. apparently is

not essential in metallurgical operations, with the possible

exception of basic steel manufacture, it will be advisable that

the production of this alloy of grades ranging between these

percentages should be discontinued in the future.

11. The proprietors of iron and steel works making use

of ferro-silicon will assist in the protection of their

workpeople, and at the same time act for the public benefit by

restricting their orders to grades of this material, either

not exceeding 30 per cent., or of 70 per cent. and upwards,

according to the special nature of their requirements.

12. But as, pending international agreement on the question,

intermediate percentages of ferro-silicon will doubtless

continue to be manufactured and sold, the issue, by the Board

of Trade, of special regulations will be necessary in order to

obviate, so far as may be possible, chance of further accidents

during the transport of this substance.

_Inter alia_, these regulations should require a declaration

of the nature, percentage, date of manufacture, and place of

origin of any such consignment.

The suggested regulations are printed on p. 291.]

ZINC

Industrial poisoning from zinc is unknown. The chronic zinc poisoning

among spelter workers described by Schlockow with nervous symptoms is

undoubtedly to be attributed to lead.

COPPER: BRASS

_Occurrence of brass-founder’s ague._—Opinion is divided as to whether

pure copper is poisonous or not. Lehmann has at any rate shown

experimentally that as an industrial poison it is without importance.

Occurrence, however, of brass-founder’s ague is undoubtedly frequent.

Although neither pure zinc nor pure copper give rise to poisoning, yet

the pouring of brass (an alloy of zinc and copper) sets up a peculiar

train of symptoms. As the symptoms are transient, and medical attendance

is only very rarely sought after, knowledge of its frequency is difficult

to obtain.

Sigel,[1] who has experimented on himself, believes that the symptoms

result from inhalation of superheated zinc fumes. In large well-appointed

brass casting shops (as in those of Zeiss in Jena) incidence is rare.

Lehmann[2] very recently has expressed his decided opinion that

brass-founder’s ague is a zinc poisoning due to inhalation of zinc

oxide and not zinc fumes. This conclusion he came to as the result of

experiments on a workman predisposed to attacks of brass-founder’s ague.

Lehmann’s surmise is that the symptoms are due to an auto-intoxication

from absorption of dead epithelial cells lining the respiratory tract,

the cells having been destroyed by inhalation of the zinc oxide. He found

that he could produce typical symptoms in a worker by inhalation of the

fumes given off in burning pure zinc.

_Metal pickling._—The object of metal dipping is to give metal objects,

especially of brass (buckles, lamps, electric fittings, candlesticks,

&c.), a clean or mat surface and is effected by dipping in baths of

nitric, hydrochloric, or sulphuric acid. Generally after dipping in

the dilute bath the articles go for one or two minutes into strong

acid, from which injurious fumes, especially nitrous fumes, develop

with occasionally fatal effect (see the chapter on Nitric Acid).

Unfortunately, there are no references in the literature of the subject

as to the frequency of such attacks.

Recovery of gold and silver has been already referred to in the chapters

on Mercury, Lead, and Cyanogen.

Mention must be made of _argyria_. This is not poisoning in the proper

sense of the word, as injury to health is hardly caused. Argyria results

from absorption of small doses of silver salts which, excreted in the

form of reduced metallic silver, give the skin a shiny black colour.

Cases are most frequently seen in silverers of glass pearls who do the

work by suction. Local argyria has been described by Lewin in silvering

of mirrors and in photographers.

III. OCCURRENCE OF INDUSTRIAL POISONING IN VARIOUS INDUSTRIES

The most important facts have now been stated as to the occurrence of

poisoning in industry, and there remain only a few gaps to fill in and to

survey briefly the risks in certain important groups of industry.

TREATMENT OF STONE AND EARTHS

Lime Burning: Glass Industry

Lead poisoning in the ceramic industry (earthenware, porcelain, glass,

polishing of precious stones, &c.) has been dealt with in detail in the

chapter on Lead. There is further the possibility of chrome-ulceration,

of arsenic poisoning, and conceivably also of manganese. Further,

poisoning by _carbonic oxide_ and carbon dioxide may occur from the

escape of furnace gases where hygienic conditions are bad. In charging

lime kilns poisoning by carbonic oxide has occurred. The report of the

Union of Chemical Industry in 1906 describes the case of a workman who

was assisting in filling the kiln with limestone. As the furnace door

was opened for the purpose gas escaped in such amount as to render him

unconscious. He was picked up thirty minutes later, but efforts at

resuscitation failed.

Carbonic oxide poisoning, again, may arise from the use of Siemens

regenerative furnaces, especially glass furnaces: details are given in

the chapter on Illuminating Gas.

_Hydrofluoric acid_ is present as an industrial poison in _glass etching_

(see Fluorine Compounds). Persons employed in this process suffer from

inflammation of the respiratory tract and ulceration of the skin of the

hands. I could not find any precise statement as to the frequency of the

occurrence of such injuries. Use of sand-blasting to roughen the surface

of glass has to some extent taken the place of etching by hydrofluoric

acid.

TREATMENT OF ANIMAL PRODUCTS

In _tanning_ use of arsenic compounds for detaching the wool from skins

and of gas lime for getting rid of hair may cause injury to health. With

the latter there is possibility of the action of cyanogen compounds (see

the chapters on Arsenic and Cyanogen).

PREPARATION OF VEGETABLE FOOD STUFFS AND THE LIKE

In _fermentation_ processes as in breweries and the sugar industry

accumulations of carbonic acid gas occur, and suffocation from this

source has been repeatedly described. Mention in this connection

should be made of the use of salufer containing some 2 per cent. of

silicofluoric acid as a preservative and antiseptic in beer brewing. In

the _sulphuring_ of hops, wine, &c., the workers may run risk from the

injurious action of sulphur dioxide. _Arsenic_ in the sulphuric acid

used for the production of _dextrine_ may set up industrial poisoning.

Poisoning from _ammonia_ gas can occur in _cold storage_ premises.

Industrial poisoning from tobacco is not proved, but the injurious effect

of the aroma and dust of tobacco—especially in women—in badly arranged

tobacco factories is probable.

WOOD WORKING

_Injurious woods._—In recent literature there are several interesting

references to injury to health from certain poisonous kinds of wood—skin

affections in workers manipulating satinwood, and affections of the heart

and general health in workers making shuttles of African boxwood. Details

of these forms of poisoning are reported from England and Bavaria. The

wood used for making the shuttles was West African boxwood (Gonioma

Kamassi). It appears that the wood contains an alkaloidal poison which

affects the heart’s action. The workers suffered from headache, feeling

of sleepiness, lachrymation, coryza, difficulty of breathing, nausea, and

weakness. Four workers had to give up the work because of the difficulty

in breathing. Inquiry was made by Dr. John Hay of Liverpool in 1908 and

by the medical inspector of factories in 1905. The following table shows

the symptoms found:

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

| | Persons Examined. |

| +-----------------+-----------------+

| Symptoms. | 1905. | 1907-1908. |

| +-------+---------+-------+---------+

| (1) | (2) | (3) | (4) | (5) |

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

|Headache | 27 | 24·1 | 18 | 22·8 |

|Feeling of somnolence | 10 | 9·0 | 17 | 21·5 |

|Running of eyes | 13 | 11·6 | 9 | 11·3 |

|Running of nose | 28 | 25·0 | 20 | 28·0 |

|Breathing affected | 34 | 30·4 | 13 | 16·4 |

|Nausea or sickness | 13 | 11·6 | 3 | 3·8 |

|Faintness or weakness | 11 | 9·6 | 1 | 1·2 |

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

The later inquiry shows considerable diminution in the amount of

complaint as to respiratory trouble. This may have been due to the

improved conditions of working, freely acknowledged by the men. Men were

examined who had complained of the effects of the wood in 1905, and had

continued uninterruptedly at the same kind of work during the interval

without any obvious further injury to their health, although they

preferred working on other woods.

East Indian boxwood had to be discarded in the shuttle trade owing to

its irritant action on the eyes. Sabicu wood from Cuba was stated to

give off ‘a snuffy dust under the machine and hand planes, the effect of

which upon the worker is to cause a running at the eyes and nose, and a

general feeling of cold in the head. The symptoms pass off in an hour or

so after discontinuance of work.’ Reference was made in the report for

1906 to eczematous eruptions produced by so-called Borneo rosewood, a

wood used owing to its brilliant colour and exquisite grain in fret-saw

work. The Director of the Imperial Institute experimented with this wood,

but failed to discover injurious properties in it. At the same time

experiments with the wood and sawdust of East and West Indian satinwood

were undertaken, but also without result.

From inquiries subsequently made it appeared that much confusion existed

as to the designation ‘satinwood,’ as under this name were classed both

East and West Indian satinwood and also satin walnut. The evidence was

clear that East Indian satinwood was more irritating than West Indian.

Satin walnut wood is apparently harmless. In the shipbuilding yards of

East London, Glasgow, and Bristol affections of the skin were recognised,

but susceptibility to the wood varied. One man asserted that merely

laying a shaving on the back of his hand would produce a sore place. The

injurious effects here seem to disappear quickly. Exhaust ventilation is

applied, but there is a tendency to give up the use of the wood.

Isolated cases of illness have been ascribed to working teak and olive

wood. In Sheffield the following are held to be irritating: ebony,

magenta rosewood, West Indian boxwood, cocos wood. Some kinds of mahogany

are said to affect the eyes and nose.

Use of methylated spirit in polishing furniture is said to lead to injury

to health although not to set up actual poisoning. Lead poisoning can

occur from the sand-papering of coats of paint applied to wood.

In impregnating wood with creosote and tar the effects on the skin noted

in the chapter on Tar are observed.

TEXTILE INDUSTRY

In getting rid of the grease from animal wool carbon bisulphide or

_benzine_ may be used.

The process of _carbonising_ in the production of shoddy may give rise to

injury to health from acid fumes. Lead poisoning used to be caused by the

knocking together of the leaden weights attached to the Jacquard looms.

This is a thing of the past, as now iron weights are universal.

Opportunity for lead poisoning is given in the weighting of

yarn—especially of silk with lead compounds.

In _bleaching_ use of chlorine and sulphur dioxide has to be borne in

mind.

In _chemical cleaning_ poisoning by benzine may occur.

In _dyeing_ and _printing_ use of poisonous colours is lessening, as

they have been supplanted by aniline colours. On occurrence of aniline

poisoning in aniline black dyeing see the section on Aniline. Use of lead

colours and of chromate of lead are dealt with in special sections.

Industrial Poisoning from Fumes, Gases and Poisons of Manufacturing Processes · 第 3 / 8 章

Some of the cases of poisoning, especially when severe and fatal, in