A considerable body of information has now been brought together with respect to the Diseases of our Mining population, but much more must yet be collected before the time will come to arrange and sum up the evidence, in order that such a decision may be arrived at as will merit general confidence, either as to the precise extent and nature of the evil, or its causes. When these have been ascertained, the relative importance of the several remedies will likewise be apparent, and the resources arising from private benevolence, will be directed into those channels which may promise to convey relief most speedily and effectually. By these remarks I by no means wish it to be inferred, that there should be any delay or hesitation in the application of measures calculated to obviate acknowledged evils. Too many such unhappily exist, and great good must be done by the carrying out of well devised plans by which any of them may be mitigated. We have only to take care that, while these useful designs are in progress, enquiry does not sleep, to be perhaps again aroused by the discovery that certain injurious agencies had been passed over with little or no attention, although perhaps still more potent than those which had been combated as the only formidable enemies. It is in this view to keeping the subject before the public that the following cursory remarks are submitted to the meeting. The extent of the destruction of life by mining operations is the part of the enquiry on which accuracy seems to have been most nearly attained. The comparison instituted by Mr. Blee between the registers of several mining and non-mining parishes, rural and urban, communicated much valuable information on the relative longevities of these two classes. The difference between them is evidently considerable, but before we proceed to calculate its precise amount from these data, we must take into consideration the respective characters of the population of the several parishes; whether progressive or stationary, whether differing in the earliness and frequency of marriage, whether the proportions of the living at any particular periods of life are changed by an influx from other parishes. In all these particulars the principal mining parishes have differed from the non-mining in that direction, which would produce an inference unfavourable to the apparent longevity of the inhabitants. In a rapidly increasing population in which marriages are early and frequent, the absolute number of infant deaths will be great, and the per-centage of deaths at every other age, as compared to the deaths at all ages, will be affected accordingly. Again, the influx of adults into a mining district at times at all prosperous, is known to be considerable, and will produce there as it does in the metropolis an increase of the adult deaths, by increasing the number of the living at the same age. If we compare the average duration of life in the parish of Gwennap, with that of Mylor, by the rough method of summing up the ages of those who died, (supposing them to have reached the limits of the decennial periods under which the deaths are classed in Mr. Blee's tables) and dividing by the number of deaths, we get 41 as the average for Mylor, and 33 for Gwennap. Mr. Lanyon has given us the average ages of miners and of labourers, who died in a large number of mining parishes during the first year of the present system of registration; the average age of the miners was 50 years and 7 months, that of the labourer 56 years and 7 months. The more recent examination of the registers of Gwennap and Stythians by Mr. Blee, (comprising the two first years of the new registration, and including only those who have died above 30 years of age) gives the average longevities of miners as 46, and 60 for other males. It may perhaps be suspected that among the latter were not a few who had formerly been miners, but who were classed under their later employments, besides that in this division a portion of persons in comparatively easy circumstances would be found, who are more likely to attain advanced age than any class of labourers. The above remark as to change of occupation applies equally to the valuable comparative tables of miners and other labourers furnished by Mr. Lanyon. The average age of 2145 working miners was 30 years 4 months, that of 1033 labourers 40 years 4 months. Mr. L. has himself directed attention to the numerous instances of the withdrawal of miners when they find their health or activity fail to other pursuits, for which the same vigour is not absolutely requisite. On the whole it may perhaps be a fairer deduction from the data hitherto collected as to the comparative longevities of miners and other labourers in nearly similar general circumstances in this county, that 10 rather than 20 years, approximates to the period by which the average life of the miner is shortened by his occupation.
I shall now pass from the comparison of different districts of Cornwall among themselves, to that of the county at large with other parts of England. Sir C. Lemon has directed attention to this in an interesting note printed in the last report of the Institution. The inferences from this comparison as stated there, are very unfavorable to Cornwall, as far as respects the proportion of deaths arising from diseases of the respiratory organs there to that in other parts of England. In fact the male deaths for this class of diseases are to the total male deaths in Cornwall 34.8 per cent., whilst throughout England they are only 24.9 per cent. The deduction was natural, that the positive amount of mortality from these diseases was much greater in Cornwall than elsewhere. But paradoxical as it at first sight appears, this high per-centage arises in great measure from the very healthiness of our county, the smallness of the mortality from other causes increasing the relative amount from the diseases of the respiratory organs, though the absolute amount of the latter is even less than in England generally. "It may in fact be laid down as a general principle, that whenever the proportion of deaths from phthisis (consumption), compared with the total deaths, is high, the absolute mortality is low, and that the absolute mortality from consumption is low also." The reason of this is obvious, the amount of mortality from consumption is comparatively with that from other diseases a fixed quantity, it will however be increased by the prevalence of the causes of other diseases, but not at the same rate as they, so that in proportion as the latter prove fatal in any district, the ratio of consumption to them will constantly diminish, whilst the absolute number of its victims is steadily though more slowly advancing. The injurious influence of a particular employment does not, of course, fall strictly within the scope of the law stated above, but it will be satisfactory to perceive that not even the direct production of consumption by mining can raise the average mortality in Cornwall from diseases of the respiratory organs to the amount which it reaches in most other counties. That it does not I will endeavour to show. The total deaths from diseases of the respiratory organs, registered from July 1st to December 31st, 1837, were

In Cornwall 711 the population being in 1831 304,785 being :: 1:428 of the population.
In Devonshire 1,169 the population being in 1831 503,118 being :: 1:430 of the population.
In England and Wales the population being in 1831 38,522 the population being in 1831 13,897,187 being :: 1:360 of the population.
In the Metropolis 6,559 the population being in 1831 1,594,890 being :: 1: 243 of the population.
In Mining Districts of Staffordshire, Worcestershire & Shropshire 647 the population being in 1831 223,457 being :: 1:347 of the population.
In Mining Districts of Northumberland and Durham 831 the population being in 1831 318,941 being :: I:384 of the population.
In Norfolk & Suffolk 1,730 the population being in 1831 682,788 being :: 1:394 of the population.

We here see that the advantage is very decidedly on the side of Cornwall in every instance but that of Devonshire, which is very slightly superior. We will now compare the relation borne by the mortality of males and females from this class of diseases in Cornwall and in the other districts respectively.

In Cornwall, males 399 or :: 1:764 (nearly) of the total population; females 312 or :: 1:977 (nearly) of the total population.
In Mining Districts of Staffordshire, &c., males 349 or :: 1:640 (nearly) of the total population; females 298 or :: 1:750 (nearly) of the total population.
In Mining Districts of Durham, &c., males 422 or :: 1:756 (nearly) of the total population; females 409 or :: 1:780 (nearly) of the total population.
In the Metropolis, males 3406 or :: 1:408 (nearly) of the total population; females 3153 or :: 1:506 (nearly) of the total population.
In Norfolk & Suffolk, males 812 or :: 1:840 (nearly) of the total population; females 918 or :: 1:744 (nearly) of the total population.

The superiority of Cornwall is still maintained over the other mining districts, and very greatly over the metropolis, even among the males, whilst it falls below the agricultural counties of Norfolk and Suffolk :: 19:21 (nearly). The female mortality is very decidedly less than that of any of the districts, and the importance of the distinction between the ratio of the deaths by different diseases, and that of the deaths by any one class of disease to the living, is strongly illustrated in the case of the females in the Staffordshire districts, the ratio of the deaths from diseases of the respiratory organs among them to the total deaths being only 23.1 per cent., whilst in Cornwall it is 27.8 per cent., a difference which had attracted the attention of Sir Charles Lemon, but it is clear that the lowness of this per-centage in Staffordshire, &c., has arisen from the large mortality from other diseases, and that the inference draw to the disadvantage of Cornwall is entirely done away with, by the fact, that while in the former districts one female died out of a population of 750, in Cornwall, one died out of a population of 977. But we will go farther and confine our consideration to the males dying of the two diseases most fatal among our miners, which are styled in the registers Consumption and Decline from these the deaths are,

In Cornwall 295 or :: 1:1033 (nearly.)
In Stafford, &c 244 or :: 1:915 (nearly.)
In Durham, &c 244 or :: 1:1306 (nearly.)
In England and Wales 12,968 or :: 1:1072 (nearly.)
In the Metropolis 1,947 or :: 1:821 (nearly.)
In Norfolk and Suffolk 582 or :: 1:1173 (nearly.)

Hence it appears, that under this mode of comparison, the most unfavorable to Cornwall, our county is still very much less fatally visited by those diseases, which are its only severe scourges, than is the metropolis; decidedly less so than the mining district in Staffordshire; that it suffers very little more than England and Wales generally, though considerably more than the agricultural counties Norfolk and Suffolk, and is still less favourably compared with the mining parts of Northumberland and Durham, the additional mortality from these diseases, being in Cornwall about one fifth. There seems then, if I am not in error, to be no evidence furnished by the report of the Registrar General, that the miners in Staffordshire, &c., do enjoy any greater immunity than those of Cornwall from these particular diseases, but this evidence is certainly insufficient for the establishment of any very positive general conclusions.
It had been my intention to have brought together and to have passed under review, the materials scattered here and there, which have a reference to the relative proportions of the causes of death among our miners, and to the agencies which give rise to them, but my leisure has not been sufficient for this purpose, and it is perhaps more desirable that such a resumé should be deferred, until the collection of facts is somewhat less incomplete than it is at present. In the course of another twelvemonth we may fairly hope that many of the deficiencies will be supplied.
I shall now confine myself to a mere indication of a few of the points on which further inquiries are needed, and of some of the additions to our knowledge on these points, which have recently accrued, or are likely to be speedily furnished. The analysis of the atmosphere in which the miner labours is perhaps the most important of all these points. The facts established by Mr. Moyle of Helston in regard to this matter (communicated to the Polytechnic Society) from which it appears that the work is at times carried on with only two thirds of the usual supply of oxygen, and in the midst of a large quantity and variety of deleterious gasses, are strongly corroborative of the opinion that much of the evil depends on the atmosphere respired. What is the comparative analysis of the air in coal mines we do not yet know. Professor Johnston of Durham has kindly furnished me with a few data connected with this subject, and as he says "I shall take an early opportunity of writing you in reference to the general subject, and of stating the opinions I have been led to form on the question of the particular diseases to which the miners are subject, especially in the lead districts and in Cornwall," we may hope to be soon more adequately informed, and there can be no doubt that whatever is wanting in the chemical investigation will be very ably supplied by this excellent chemist. While speaking of him I will allude to another branch of the subject, on which he has furnished me with the paper I hold in my hand. It is a reply to a number of queries relative to the condition of the colliery village of Hetton: of these I will only notice that which gives the amount of wages; this is, "Hewers 3s. 9d., putters 3s. 9d., banksmen 4s. 7d., waggon-men 3s. 6d., engineers 3s. 4d., masons 3s. 5d., smiths 3s. 2d., per day, with house, firing, and garden in addition ; the hewers for six, and all others for twelve hours per day: boys about 16 years of age 2s. 3d., per day." You will see in this single statement a part of the explanation of the comparatively healthy condition of the colliers.
It is to be regretted that little or no attention seems hitherto to have been paid in the neighbourhood of the mines in the Hartz mountains to the relative health of the miners before and after the introduction of the methods of conveying them up and down the mines without climbing. On a collateral branch of this inquiry the analogy existing between miners and seamen, from the climbing of ladders involved in the occupation of each, I have been favoured with an interesting communication from Mr. Weale of the Royal Hospital, Plymouth [see below], a gentleman of very extensive experience in the diseases of seamen, and a most excellent pathologist. I will quote but one passage from his letter ; "I may repeat that I cannot attribute much mortality amongst miners to their habits of climbing, but must look for its cause in the Climate that they are subjected to, and its vicissitudes."
The amount of destruction of life produced by accidents in mines has attracted attention recently, and some facts communicated to the public by Mr. Blee are calculated to excite a good deal of alarm in reference to this point. That these facts would of themselves lead to inferences greatly too unfavourable is rendered extremely probable by the comparatively low ratio of the deaths caused by violence throughout the county, as appearing from the Registrar General's Report. I may also state that I was yesterday informed by a gentleman largely engaged in medical practice in St. Agnes, that he could not recollect a single instance of violent death occurring in a mine in that parish during the last two years. I have applied to the Coroner of this division for evidence on this subject, and hope to be provided by the other gentlemen filling the same office in other parts of the county with the exact number of fatal accidents which have occurred. It does not seem necessary to detain you with any further remarks. The heads of the subject, demanding more especial investigation, have been long since drawn up, and it is to be hoped that the committee appointed by the Polytechnic Society for this purpose, will issue some papers of queries, entering into sufficient detail, and embracing a field sufficiently wide to lead to the production of a body of unexceptionable evidence, such as may be conclusive as to the nature and relative importance of the mischievous agencies which are operative in different mining districts, and the several remedies for these evils, will, it is believed, be furnished by the ingenuity and benevolence of the county with more than equal speed.

Oct. 2.—A letter from Mr. Weale, of the Royal Naval Hospital at Plymouth to Dr. Barharn, on the diseases of Miners and Sailors was read, of which the following is an extract,

" Royal Hospital Plymouth, 6 August, 1840.
"I feel much pleasure in being able to render you any assistance, and am glad to find that our opinions in some measure coincide. Statistics are extremely fallacious (at least I have found them so); but on the other hand it is wrong to generalize from individual observation, however ample: so I give you the following observations with much caution as to their general truth, though, I can vouch for their accuracy as far as I have myself seen.
"During a residence of a few weeks in a mining neighbourhood, I occasionally visited the mines, more with a view of observing the labourers employed in them than anything else; and for the purpose of forming my own conclusions as to the influence of their occupations on their health and duration of life. To obtain any correct information on the subject of disease from people so very ignorant was almost impossible, but, as far as their descriptions went, my belief, that Phthisis was the destroying angel among them, became strengthened, and my preconceived notion of the frequency of heart disease (alone) weakened; for almost all the sequelae of the latter were wanting, in the descriptions of the terminal scenes of their friends; and those symptoms referred to the heart were most probably merely the secondary affections of that organ, superinduced by pulmonary disease.
" When we consider the vicissitudes of temperature to which miners are subjected, the breathing of a damp atmosphere abundantly filled with noxious gases and irritating particles, we cannot be at a loss for excitants of a disease to which they had an hereditary tendency; as the children of miners follow their father's occupation. Then again, their sudden transitions of climate, if I may so say, and their coming out of a close moist chamber into the chill cold atmosphere of a hill top or barren moor. In the above causes we have abundantly enough to account for Phthisis; but we may enquire what other complaints were the most likely to be their effects; and also how far the climbing of ladders tended to excite a morbid condition in the heart. From what I saw of their ascent and descent, I do not think that a healthy man, would, under ordinary circumstances, suffer any Cardiac distress. Very probably many cases of Rheumatism occur and occasionally the Pericarditic form, thereby rendering the heart more prone to abnormal excitation on exertion. Tubercles in a crude form, rendering the transmission of the blood through the lungs very difficult, particularly during exercise, rnay produce hypertrophy of the right side of the heart, or perhaps of the whole organ. In asthma the heart seems to be implicated, and dilatation is frequently present; now this disease is very general amongst those who are employed in stone cutting. May not miners also suffer from it and its consequences.
"A late writer Mr. Porter suggests the probability of Rheumatism being one of the causes of atheromatous deposit in the coats of arteries; and where such morbid change takes place we find loss of elasticity, sacculation of the aorta, destruction of the valvular apparatus, and hypertrophy of the ventricles as a consequence. Does such a train of symptoms ever present itselt among miners?
"In the above hasty remarks, I have no other end than to form a contrast with the most prominent diseases of another climbing class, sailors. On reviewing the cases which occurred to my observation for some years past, both here, and in a large hospital in a seaport town in Ireland, I am led to the conviction that three out of four sailors die of Phthisis. The mortality from that complaint among those in the navy is perhaps greater than in the merchant service, as their stay in warm climates is more protracted and they are subjected to the more depressing influences of rigorous discipline and separation from home, when perhaps unused to them. Palpitation is not infrequent, but it is usually the consequent of rheumatism, and though exasperated by exertion was not in the first instance produced by it. What strengthens my belief in this is, that palpitation is of the two more frequent amongst Marines, who scarcely ever go aloft, and that the best specimens of organic change, which have occurred to my notice, were found in that class.
"A few cases of increased action preventing men from going aloft were attributed to violent exertions either in lifting weights or pulling and hawling, &c; but to the mere fact of ascending or descending the rigging, I cannot impute a single instance.
"Amongst Gymnasts I have seen a few cases of Hypertrophy, but those were the result of inordinate exertion interfering with the respiratory actions, and in some cases made by persons not gradually trained to it. Aneurisms are sometimes the cause of death in tumblers, but we must be aware that violent and sudden flexion and extension of arteries predisposes them to such a change as aneurismal dilatation; nor can we be surprised when we see the flexion of the spine effected in a way so opposed to the laws of our system.
" We may draw a parallel between the miner and the sailor. One works from 8 to 10 hours in a damp mine with an indifferent ventilation, perhaps suffering from intense heat, then he lays aside his labour, and ascends into a cold dry air. The other sleeps in his hammock between decks in a confined space, perhaps in a tropical climate, is suddenly roused to go aloft, and changes his temperature several degrees. Or perhaps after enjoying the genial warmth of an Italian climate, he is ordered home and detained by adverse winds in the channel during January or February, with only such clothing to protect him as he had in summer weather. Can we be surprised in either instance if they become victims to Phthisis? Besides, both are careless, and little heed the warning voice of incipient disease; amongst sailors acute disease often sinks insensibly into a smouldering insidious form, and Pneumonia, Bronchitis, &c. gradually assume the character of Phthisis. Persons often talk of "heart disease" without even knowing what constitutes it, and confound the mere symptomatic forms with the idiopathic. Even in pathology many apparently good practitioners have made so little advance that their cadaveric observations can be little relied upon, much less their Diagnosis; and the vulgar so generally refer any affections of the chest to the heart, that we cannot wonder why miners suffering from Phthisis, should be said to have heart affections. Again I may repeat that I cannot attribute much mortality amongst miners to their habits of climbing, but must look for its cause in the Climate that they are subjected to and its vicissitudes.
" Since writing the above, a case confirmatory of my opinion, presented itself. A sailor who sank rather suddenly, with dyspnæa, quick and full pulse, dry cough, and dulness of the middle of the Thorax, with other unequivocal symptoms of Cardiac disease was examined. The lungs though congested were structurally normal; The Heart, double its natural size, was dilated on the right, dilated and hypertrophied on the left side; the Aortic semilunar valves rendered useless by vegetations arising from deposit of atheromatous matter in their duplicatures; similar deposits immediately under the internal coat of the aorta as far as the turn of its arch. In this case, which bears a strong resemblance to many others I have seen, it is evident that the cardiac disease was not produced by climbing, but that the Hypertrophy, &c. were secondary to the loss of mechanical power in tha aortic valves. The origin of his ailments was stated to have been subsequent to the period when he was in the habit of going aloft, as he had been for a considerable time one of the crew of the San Josef a harbour ship; and was employed as coxswain of a boat, a post requiring little if any exertion. I have swelled these remarks to a greater length than I at first intended, but trust that they have not exhausted your patience. I feel anxious to aid you (if I can be so fortunate) in your benevolent purpose. If I can be of further use to you it will give me great pleasure."*

* note. - The talents and acquirements of the writer of this letter were lost to the world by his death, within a few months after it was penned. Mr. Weale had made the best possible use of the great facilities afforded for the observation of the diseases of seamen, in the Naval Hospitals in which he was employed. The structural changes resulting from these diseases were noted by him with scrupulous accuracy, and recorded with singular pictorial skill. The fruits of this skill remain behind him, a durable monument, which will it is to be hoped be rendered accessible to the medical public, that the benefit as well as the memory of Mr. Weale's talents may be prolonged and extended. C. B.

Twenty Second Annual Report of the Royal Institution of Cornwall, 1840. pp67-73, 34-37.