smoke is no necessary concomitant of that prosperity.

If the outer air is thus polluted, the workshops and factories in which so many gain their daily bread, are likely to be still more heavily charged with impurities. At one time undoubtedly this was the case, and it has been shown by Dr. Greenhow, in his report to the Privy Council, and more recently by Dr. B. W. Richardson, in his lectures before the Society of Arts, that very grievous evils result from the breathing of air laden with fine particles of dust of various kinds.

Dr. Greenhow, in his inquiry into the causes of lung disease, mentions amongst those who suffer most from this cause the grinders of Sheffield and Birmingham, the brass-workers of these towns and Wolverhampton, the tinmen and enamellers of hardware and button-makers of Birmingham, and the card-room and cotton and weaving operatives of Nottingham and other places.

Fine particles in the air, especially if they are sharp and irritating, do mischief in several ways. When dust is breathed by a healthy person, there is always an effort made by nature to prevent it from settling in the lungs. First, when it touches the opening of the windpipe, it causes an irritation there, and a message is at once sent by the telegraphic | apparatus of the nerves that an intruder is trying to make his way in, the head office signals the breathing muscles to act, and immediately they contract spasmodically, and an uncontrollable cough is the result. If this fails at once to get rid of the offending particle, at the same time that the cough is ordered, certain little glands that are placed around the entrance to the air-passages are made to pour out a quantity of mucous, or phlegm, that envelopes the little speck of dust, and prevents it any more from touching the tender membrane upon which it at first fell. Just as a particle of coal or dust getting into the eye causes the tears to pour forth and wash it away, so an irritant at the opening of the windpipe brings a flood of glairy fluid which both covers up the particle and carries it into a position from which a further act of coughing will expel it.

If the dust should have been carried a little further into the air-tubes, a still further provision is made to convey it away before it has done harm, and this is accomplished by a very beautiful arrangement. Throughout the whole of the air-passages the lining skin-the mucous membrane, as it is calledis provided with myriads of most minute and delicate little hairs, called 'cilia,' less than a thousandth of an inch in length; these hairs are continually in movement, waving like a field of corn bending before the wind,' and then rising into the erect position, and as they always tend into one direction, namely, towards the mouth, they gradually carry any secretion, and whatever it may hold within its grasp, steadily and surely out of the lungs, and into the safer track leading to the stomach. If the particle is larger or more irritating than usual, directly it gets to the top of the windpipe another cough is ordered, and the morsel is expelled forcibly along with expectoration, and is ejected by hawking and spitting. This is the exquisitely beautiful mechanism that naturally guards the delicate lungs from harm.

In this town many of us have doubtless had opportunities of noticing the fact that after breathing in smoky air for a time, especially during the presence of a fog, the phlegm that is brought up sometimes the next morning is of a dark, almost black colour.

This is owing to the presence of fine particles of soot or coal-dust, which, if suffered to remain, might have caused inflammation or other damage to the lungs.

For this arrangement does not always work. It is a law of nature, a law of both the moral and the material world, that when a warning is frequently repeated and disregarded, the sensibilities get deadened, and the safeguards so mercifully provided are no longer to be relied upon. To a certain extent this is well, for it permits men to adapt themselves to circumstances in which otherwise they would be unable to live at all; but, in the case now before us, the results are often very disastrous.

For consider what takes place when, after many efforts of coughing and spitting, the nerves and muscles we have seen working so benevolently at length lose their power, or become no longer disposed to exercise it. The irritating particle lodges for a time upon the delicate membrane, and causes it to inflame in the same way that a speck of some foreign body in the eye causes it to become inflamed and shot with blood. If it is not removed, the membrane swells, becomes reddened and heated, and presently it pours out more and more of its secretion, but now it is no longer healthy mucus, but an altered thickish fluid, that has to be brought up by many acts of coughing. If the irritation is still kept up by inhalation of fresh particles of dust, the condition remains a constant one, and the workman becomes subject to what is called chronic bronchitis, a slow, lingering form of inflammation of the lining skin of the air-tubes; the cough often overstrains the minute little air-cells, and they lose their elasticity and cannot empty themselves. The patient begins to pant and wheeze at his work, and gets what is called potter's or grinder's asthma.

But in other cases the evil does not stop at the lining membrane of the lungs, the inflammatory agency penetrates more deeply, the blood-vessels are altered in their size and in their power of passing in the blood, the hard-worked tissues of the lungs are imperfectly nourished, dense tough material takes the place of the soft spongy texture found in health, and then a condition hardly to be distinguished from consumption is planted upon the lungs. And it runs a very similar course to that most trying malady, gradually ruining the structure of the breathing apparatus, and leading to a painful, lingering death.

These are only too true pictures of what is now taking place in many thousands of cases throughout the manufacturing districts of England.

Many useful lives are shortened through this cause. A fork-grinder once said to Dr. J. G. Hall, of Sheffield, 'I shall be thirty-six next month, and you know that is getting an old man at our trade.' Another, a young man of about twenty-six years, said he reckoned in about two more years at his trade he might begin to think of dropping off the perch,' adding, 'you know a knife-grinder is an old cock at thirty, and at that time, in the year 1865, many of them died miserably before the age of thirty.

Happily, in the last few years, means have been applied to diminish the evils arising from this kind of work. It is to the honour of British manufacturers that they have always been ready to adopt means of saving life. At the late exhibition of life-saving apparatus at Brussels, Englishmen took the largest number of prizes, and a few years ago, when Mons. Freycinet was commissioned by the French Govern

most important of the sources of the pollution of air, namely, respiration. It is at once the most inevitable of evils, and perhaps the most easily remedied. No man can help spoiling the air he breathes, but owing to the bounteous provisions of nature, there are few who cannot get fresh supplies of tolerably good air to take its place.

But let us see what changes air undergoes by being breathed.

In every 100 parts of the air that we take into our lungs, there are, as we have seen, twenty-one

great cause of that fearful disease, the true tubercular consumption, from which so many thousands die every year.

It will be worth our while to examine the evidence upon which this conclusion rests. (To be continued.)

THE

parts of oxygen, but when it returns from the chest SANITARY

it contains only thirteen parts, the other eight parts have been removed from the air by the little blood corpuscles floating in the current of the blood rushing through the lungs.

But expired air is not only deficient in oxygen, it

contains a much larger quantity of the choke-damp,

or poisonous carbonic acid than it did on entering; instead of only three or four parts in 10,000, it now holds nearly 500 parts in 10,000.

The oxygen previously inspired has met with a quantity of fuel in the tissues of the body and in the blood, has burnt it up, and has produced this large quantity of charcoal vapour.

One pair of lungs pours out into the air in this way, in twenty-four hours, about as much carbonic acid gas as would be formed by burning eight ounces of pure charcoal, and at every breath a full-grown man thus alters rather more than a gallon every minute by his respiration, but he really spoils nearly one hundred times the quantity he breathes, for air that contains six parts of CO, in the 10,000, has been found to be unfit for further breathing. And there is yet a third way in which breathing changes air. It becomes loaded with a larger quantity of watery vapour, and this vapour contains a certain amount of putrefying animal matter. If the vapour of the breath be condensed into a liquid, as may easily be done by exposing it to a cold temperature, it may be examined by chemical processes, or by the microscope. This I have frequently done, and have estimated the quantity and kind of organic matter given off, both in health and in disease. It would be sufficient, however, to prove to anyone the nature of this product of respiration, to keep it for a day or two in a warm place, and it soon gives off a putrid smell.

It will also at once change the colour of a solution of permanganate of potash, the basis of Condy's fluid. The disagreeable odour of close air, which has been charged with impurities from the breath, is due to the accumulation of this exhalation. It is

also the chief cause of the noxious nature of respired air, and will kill without any other ingredient being present. An American physician, Dr. Hammond, once kept a mouse under a bell-glass, took care that it was supplied with plenty of oxygen, and removed the carbonic acid and watery vapour; but allowed the organic matter to remain; the mouse died in 45

minutes.

How rapidly fatal air containing all the products of respiration is, was terribly proved by the cases of the Black-hole at Calcutta, the prison in which 300 Austrian prisoners were put after the battle of Austerlitz (260 dying from it very rapidly) and by the case of the steamer Londonderry.

But air vitiated by respiration produces much greater havoc than this every day, in nearly all our large towns.

It is beginning to be acknowledged that it is the

SANITARY RECORD.

SATURDAY, JANUARY 6, 1876.

The Editor will be glad to receive, with a view to publication, announcements of meetings, reports of proceedings, and abstracts or originals of papers read before the members of any sanitary or kindred association.

CATCHING TRAINS.

No one who has had the opportunity of comparing an English station with a continental one when the train is in, can help feeling what a contrast they offer. There all is comparatively orderly, and the passengers have all to be in good time, for the barrier is closed some minutes before the train is due. Here there is a regular rush which thickens as the last minute arrives, and it is the rule rather than the exception for some one to be pushed into a carriage as the train moves off. The frantic efforts made alike by old and young, with and without carpet bags, to secure their train is especially conspicuous at Cannon Street about five in the evening. Why these persons cannot start a minute earlier, so as to do away with the necessity for this overstrain, as it turns out to be for a proportion of them, is an inscrutable mystery to those who do not follow the same practice. The prevalent custom of just catching a train is every now and then productive of a serious lesson to those who practise it. A death from such sudden effort is not at all uncommon with persons of advanced life; and cases are every now

and again being recorded in the papers of elderly persons who have died suddenly after or during an attempt to catch a train, or at other times an omnibus. It is only a few months ago that an aged female died on the platform of the Denmark Hill station after an effort which was too much for her. Still more recently even a sadder case has occurred.

A gentleman and his son the other morning were a little late for their customary town train on the South Western, and had to make a run for it.' They were successful in their attempt, and caught the train. But the younger gentleman gasped for breath, made a few motions with his hand, and would have fallen if he had not been caught. Before the train arrived at the next station he was dead.

fatal symptoms of the heart, preceding ruptures are found at times with a clot blocking the opening. These are extreme cases truly, but they demonstrate beyond doubt that serious injury may be inflicted upon the heart without instantaneous consequences. A distinguished physician over-exerted himself some time ago in an Alpine climb of unusual severity, and had an attack of cardiac syncope of very serious character near the Eggischhorn, necessitating an instant resort to the recumbent posture. Great caution was required to reach the inn, though no general fatigue was complained of. At three o'clock in the morning a similar attack awakened him quite suddenly, showing how effort during the day may be followed by great disturbance of the heart afterwards. This physician is a young and healthy man, else that night attack might have been fatal to him ; just as much so as the original attack during the alpine ascent. With elderly people sudden exertion during the day is undoubtedly one cause of failure of the heart's action during the night; so that the effort may really be only apparently made with impunity.

Nor are these fatal results the only untoward consequences of sudden demand upon the powers. Much more commonly the effort is followed by shortness of breath on exertion, by palpitation easily in

The verdict of the coroner's jury, following the opinion of the medical witness, was to the effect— "That death arose from syncope of the heart,' brought on. by running, after a hearty meal. Such was the end of a gentleman only thirty years of age. The wonder is not that so many fatal cases are recorded, but that there are not more. The number of persons, not all young, who systematically delay till the last moment, and then make a rush for their train, is to be counted by hundreds on each of the great lines into London. A large majority of these are persons who are in no wise trained, or otherwise prepared for such efforts. The bulk of them are men whose ways are sedentary, and who rarely make an effort of any importance at any other time. There is no preparation on the part of the internal organs to undergo sudden strain; and when they are subjected to it, sooner or later untoward consequences result. In athletes long and careful preparation precedes violent effort, and even then unpleasant results are not unknown. But sudden strain upon organs not so trained is much more liable to induce disastrous sequelæ. Of course it must be admitted that the proportion of fatal accidents is very small compared to the large number of those who are given to the practice of having to rush for the train, and consequently many are strengthened thereby induced, by incapacity to undergo any violent effort, their injudicious procedure. But the present case shows that even with young and apparently if really not quite healthy persons there is danger and risk in so doing. The father did his run with impunity, while the younger man died; showing that it is not necessarily the aged whose tissues fail under sudden demand. So far as can be ascertained, the deceased gentleman was well and in good health. He certainly may have been the subject of some occult disease of the heart or great vessels, such as occasionally are found, unsuspected and giving no sign, but it is by no means necessary to assume that such was the case. He made a sudden effort after a hearty meal, and syncope of the heart followed. The hearty meal diminished the space in which the heart beats, and the organ, taxed by sudden effort at the same time, stopped, and the gentleman died. This is an accident which if rare, is one to which any of those persons who habitually tarry to the last minute and then have to make a sudden effort, is liable. It does not follow that there is only danger when the heart and arteries are the subjects of chronic changes, and so less able to support a sudden demand; it exists even for those who are too young to have entered upon degenerative changes.

The dangers of such sudden strain are not confined to failure of the heart upon the spot. Very commonly in those cases where apparently healthy old people are found dead in bed there may be traced out a history of sudden effort made during the preceding day. The overstrain]so put upon the heart does not manifest itself fully at the time, but during the sleep of the ensuing night. Even in cases of

and even by enfeeblement of the powers for some
considerable time after the effort which produced
these consequences has been made. A chronic con-
dition of impaired wind is often brought about by
undue effort, even in the young and comparatively
robust, who are accustomed to demands upon the
powers.
powers. It is impossible, perhaps, to impress upon
business men the risks that they run from their
habits of delay until it becomes necessary to make
a severe effort to catch their train. Doubtless it is
done by a multitude of persons as a regular practice,
but absolute impunity cannot be secured; and at in-
tervals some one pays the penalty, and furnishes an
illustration of the dangers which beset the practice.

RAILWAY ACCIDENTS.

WITHOUT wishing or intending to add to the troubles and anxieties the Great Northern officials and directors are naturally just now experiencing, we will venture to call attention to a few of the defects in their system which promote accidents.

In the first place it has long been notorious that the brake-power in their long and fast trains is ridiculously inefficient, and the time that has elapsed since the Abbot's Ripton catastrophe has not been utilised as it might and should have been, in remedying this dangerous weakness. As if to still further their liability to accident from deficient brake-power, it is the custom on the Great Northern to utilise their guards as parcels porters. Even in the fastest trains a guard will often be so crammed with parcels that from King's Cross to Peterborough his whole atten