LEAD), and ground glass, and according to Mr. Prescott (see his valuable work, "Strong Drink and Tobacco Smoke," London, 1869), the acorn cup of the Valonia oak, growing on the shores of the Mediterranean, which is imported for the benefit of tanners. Most of these adulterations may be detected by examining the powder with the microscope, and by tests already given. Consumption.-In France the Government have the monopoly of tobacco, and in 1867 we learn that the imperial manufactories sold no less than 248,652,000 franes' (£10,360,500) worth of tobacco, and that the net profit which accrued to the revenue from this sale was 177,752,435 francs (£7,406,351, 9s. 2d.) The following statement exhibits the amount and value of the tobacco imported into this country during the years 1870–72 :— 3,667,585 1,145,150 1,563,882 Unmanufactured. 45,549,700 Tortoise, Land-The land tortoise is eaten by the inhabitants of Italy and the Levant, by the natives of the Amazon, South Africa, India, and by the North American Indians. Payen considers its flesh a wholesome food, and the late Dr. Livingstone found it an agreeable meat. Trades, Injurious-There are a variety of trades the exercise of which influences greatly the health of the workmen. Among these influences we do not, of course, include such as are in no degree connected with the nature of the employment-as, for instance, overcrowding in workshops, impure air from defective ventilation, draughty and damp rooms, &c. But there are hurtful conditions directly arising from the nature of certain avocations which may be traced usually to one of two causes (or to both combined)-viz., dust and gases, or volatile emanations. Dust.-The diseases to which dust in the arts gives rise are, principally and primarily, chest affections. Dr. Hirt gives the following instructive table showing the relative frequency of phthisis in dusty trades (Die Krankheiten der Arbeiter, Leipzig, 1873) :RELATIVE FREQUENCY of PHTHISIS amongst Workmen working in Dusty Trades. 1. Metallic Dust. In 100 Patients. Needlemakers Filemakers Lithographers : Suffering from Phthisis. 69.6 62.9 48-5 Joiners Coachmakers Pastrycooks Millers Bakers 2. Mineral Dust. 80-0 Grindstone-makers 40 0 Stonecutters Plasterers 36-4 19-0 1476 12.5 11-6 10.9 7.0 1817. It is an affection specially distinguished | a dust which chemical analysis shows to conby carbonaceous sputa, and prevalent amongst sist mainly of silica. those working in dust, either of coal or charcoal. It is essentially a fibroid phthisis, brought on by irritation from carbonaceous dust. Tabacosis was first described by Zenker; he found, on examining the bodies of two work. men in a tobacco manufactory, the lungs infiltrated with tobacco dust. When a similar affection comes from inhaling cotton fibres, it has been called lyssinosis. With regard to metallic dust, it is pretty well established that the finer the dust, the more injurious are its effects. Dr. Hirt gives the following table, showing the affections and mean duration of life among farriers, cutlers, lockmakers, and filecutters : Most of the metallic dust simply acts mechanically, the effects varying in intensity according to the fineness and sharpness of the spicule; others act both mechanically and as poisons for example, copper dust and the fumes to which brasiers, turners, and workers in bronze are exposed to. Of trades giving rise to mineral dust more or less injurious we may mention diamondpolishers, grindstone-makers, workers in flint, in marble, in granite, in basalt, in mica, in gneiss, in sulphate of baryta, pumice-stone, and hæmatite. All these substances give rise to dusts which have induced various lung affections. According to Peacock, the mean age of the grindstone-makers does not exceed twenty-four years, and they nearly all become phthisical. Workers in soft stone, in plaster, in chalk, and in clay suffer little from lung affections, perhaps because the particles are soft and large. It appears remarkable that carpenters and masons suffer from similar diseases, and their mortality is the same. workmen in charcoal is diminished requires farther investigation. At present it would appear that the dust of carbon exercises a preventive influence. Dr. Hirt gives the mortality of miners as 1505 per 100; of charcoal- burners as 1330; and of chimney-sweeps as 2.291. Workers in tobacco suffer severely at first, and some few are attacked by lung affections. The mean duration of life appears to be from fifty-three to fifty-eight years. (Annales d'Hygiène, 1874.) Of all the vegetable dusts, cotton fibre appears most hurtful. There is great irritation of the larynx, anæmia, frequent cough, and expectoration of a sputa containing cotton fibres. The mortality is greatest among the women. The manufacture of wadding, of linen and hempen stuffs, also gives rise to dust-less injurous, however, than that produced from cotton. The mean duration of life among weavers, according to 336 observations, is 51 to 97. Among those who work in hemp it is still less Plasterers, workers in serpentine, slate-quar-viz., from 42 to 45. riers, and workers in graphite are fairly healthy. When we come to vegetable dusts, the mortality and liability to phthisis diminish. Thus in 100 patients breathing Inorganic dust Organic dust No dust Suffer from Phthisis. Per cent. The mortality and maladies of workers in wood are given in the table at the top of the next page, and present nothing remarkable. The dust of chicory and madder does not appear to have any injurious effect; the coloured woods--sandal, campechy, &c. - on the contrary, cause much irritation. Workers in quinine and cinchona barks suffer from an That the mortality from phthisis amongst eruption on the skin, with itching and fever. Charcoal dust. 26.0 17:0 110 11 In the preparation of the two mushrooms Boletus ignarius and fomentarius, the spores affect the mucous membranes of the eyes and nose, and produce epistaxis, ophthalmia, headache, and other ailments. The dust of corn, wheat, barley, &c., when in great quantity, produces bronchitic and emphysematous affections. The most frequent disease among millers is pneumonia-viz., 203 out of every 100 patients. Their mean duration of life is forty-five years; mortality, 1726 per cent. Bakers and pastrycooks do not suffer from chest diseases so much as millers; but, on the other hand, the irregular hours produce other diseases, especially of the digestive and nervous organs. Suffering from- : Women engaged in sorting feathers suffer considerably from inhalation of dust. Bonedust does not appear very injurious, for workmen in the grinding of bones are fairly healthy. Of mixed dust, one of the most dangerous is that which the artisan employed in cutting and polishing glass breathes. Diseases of the chest prevail amongst them in the large proportion of 80 per cent. The mean duration of life of the polishers does not exceed fortytwo years. Ragpickers are not alone exposed to the mixed dust from the rags, but also to contagion. Papermakers are exposed to similar dust, at all events in the preliminary operations. The mortality is 1.20 per hundred. Gases and Volatile Emanations.—With regard to gases, it appears certain, from the researches of Baiviston, Lombard, and others, that some produce phthisis, more especially the irrespirable gases, such as chlorine, sulphurous vapours, nitrous acid, vapours of lime, turpentine, &c. Others, especially the toxic, have no influence in this way, for they are absorbed by the blood and influence the Heart Disease, Mean Duration of Life. Mortality per cent. In 100 Patients. whole economy. To the latter class belong carbonic oxide, carbonic acid, sulphuric anhydride, and carbonic disulphide. In the manufacture of straw hats the workpeople are exposed to emanations of sulphurous acid, which cause anæmia, cough, sneezing, and salivation. In the making of matches with common phosphorus, very deleterious fumes are given off, causing caries of the jaw. See PHOSPHORUS. Jewellers in various operations-in the quartation, refining, &c., of gold or silver-are exposed to nitrous acid vapours. Phthisis prevails among them in the proportion of 186, pneumonia in the proportion of 84 for every 100 sick. Their mean duration of life is fifty-three years. Gilders are more unhealthy than jewellers, probably from breathing mercurial fumes. Their mean duration of life does not exceed forty-four years. Bleachers are exposed to chlorine gas, alkaline vapours, smoke, and humidity; they are not healthy. Their mean duration of life is fifty-eight years. Engine-drivers are exposed to unequal heat and continual commotion; they often breathe an impure atmosphere, especially in such places as the Metropolitan Railway, and suffer considerably from rheumatism, disorders of the digestion, &c. The mean duration of the drivers of locomotives on the Friborg-Breslau line is only thirty-five years.-(HIRT.) Those employed in the engine-rooms of steamboats have a mean duration of life of fifty-seven years. (LUBSTORFF.) The nightmen and those engaged in sewers are sometimes overpowered by sulphuretted hydrogen and other noxious vapours; they also suffer much from disorders of digestion and other ailments, but we have no trustworthy statistics with regard to the prevalence of fever amongst them. According to Hirt, their average duration of life is from fifty-five to sixty years, so that it cannot be extremely prejudicial. Tanners, curriers, leather-dressers, catgutmakers, soap and candle makers, and butchers are exposed to putrid emanations, without, however, any sensible effect. The following table gives the relative frequency of diseases in some of the classes mentioned : Workers exposed to zinc fumes are not unfrequently seized with symptoms of fever, which at the end of three or six hours terminates by a profuse sweat and a long-continued sleep. In the grinding of oleaginous grains very disagreeable vapours are given out, but they have little influence on the health. According to Dr. Hirt, only 3 per cent. of patients following this employment suffer from phthisis. A large number of workmen in the arts are exposed to the vapours of turpentine-c.g., painters, varnishers, and others. The characteristic odour of violets can often be detected in the urine of these men, showing that the turpentine has been absorbed. They fre ... quently suffer from colic and derangement of the digestive organs. In the preparation of caoutchouc, especially in its vulcanisation, there are large quantities of vapour given forth, particularly carbonic disulphide; great care is, however, taken in the ventilation of the works, and poisoning is rare. The mean duration of life of caoutchouc - workers is about fifty-seven years; mortality, 1:393 per cent. The tarry matter given out in the manufacture of paraffine is not very injurious, but eruptions of the skin are common among the workmen. Their mean duration of life is from sixty to sixty-two years. In order to prevent the injurious effects of dust upon workmen engaged in such trades as dry grinding, &c., artificial ventilation inducing strong currents of air is absolutely necessary; and as in these particular trades there is always steam-power, some method either of propelling or extracting air is easily applied. But many of the cases require special treatment, especially with regard to noxious gases and vapours; for example, ammonia in small quantities prevents the bad effects of working in nitrate of silver, and saucers of turpentine distributed about a room greatly mitigate the vapours of common phosphorus. Che mical means of this kind should, however, be only considered as accessory to good ventilation. For observations on miners, see MINES. See also PHOSPHORUS, &c. It is absolutely certain that the odours from bone manufactories and tanyards, and a great many other very offensive trades, cause no injury whatever to the health of either those engaged in them or of those living in the vicinity; such odours are, nevertheless, nuisances of a public character. Trades, Offensive-The general supervision of trades is expressly cast upon urban sanitary authorities by the enactments given at the end of this article. The sections of the Public Health Act relative to the establishment and to the regulation of trades must be interpreted by sanitary authorities according to the spirit which evidently actuates the law on this point, and that is, not to interfere or control manufacturing industry, on which the wealth of England depends, unnecessarily; but, on the other hand, where there is evident and considerable public annoyance and injury, to take action at once, as authorised by the statutes. As the initiation of proceedings will in nine cases out of ten be taken on the opinion or advice of the medical officer of health, it is absolutely necessary for such an officer to practically acquaint himself with the details of the different manufacturing industries in his district. These are always best studied in the building itself; for though printed descriptions will give a good idea of the general principles on which an industry is carried out, the details are far more easily learned by witnessing the different processes in operation. The principal ways by which a trade becomes a nuisance are storage of offensive materials, the escape of volatile gases or emanations into the atmosphere, and the improper disposal of fixed refuse, whether liquid or solid. as raw hides, bones, hoofs, &c.-providing the sheds or storage places are properly constructed, and the substances are conveyed from the storage-houses to the manufactory in closed air tight boxes, carts, or other receptacles, offence is hardly possible; but if there is a nuisance from neglect of any of these precautions, there can be no excuse on the part of the manufacturer, and he should be made to abate the nuisance immediately. Nuisances and injuries from the escape of volatile gases or emanations into the atmosphere, may be, for the sake of convenience, divided into (1) organic vapours; (2) gases partly organic and partly of definite constitution; (3) acid gases. 1. By the term organic vapours is meant gases the greater portion of which are composed of highly offensive emanations of unknown chemical composition; many of them are probably bodies built upon the type of ammonia. Such vapours are evolved in the melting of fats, in the making of size and glue, of manure, in the boiling of oil, in the boiling of bones, in the dressing of tripe, in the manufacture of glucose, and in many other processes carried out on a considerable scale. The general remedy for all these cases is to see that the operations are conducted in closed boilers, and that the organic vapours, deprived of steam, are carried into the furnace fire to be there consumed. (This is not always possible; for instance, in the case of making American cloth inflammable spirit is used, hence if the vapours were passed through a fire an explosion might result.) 2. In a great many operations the gases are of a very mixed character; for example, in the distillation of oils and fats, sulphurous acid, acrolein, and other fumes are evolved; and in the manufacture of superphosphate of lime, tetrafluoride of silicon is mixed with organic and acid vapour. In some of these cases, the gases have to pass through one or more chambers, scrubbers, or purifiers before they are permitted to mix with the atmosphere. Thus in the latter case, the gases evolved from the treatment with sulphuric acid, of coprolites, crushed bones, and animal refuse, are led by a shaft first to a chamber where they meet with a spray of water which decomposes the tetrafluoride of silicon, part being precipitated as hydrate of silica, and part dissolved as hydrofluosilicic acid; the gases then pass on to a coke scrubber or condenser, and lastly through a lime purifier. In the case of the manufacture of coal gas, also, there are very numerous and complex products given off, but no simple means for As to the storage of offensive matters-such its purification, and at the same time for the |