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Les diagrammes suivants illustrent la mdthode. rrata o 3elure, □ 32X 1 2 3 1 2 3 4 5 6 L i / ^r i ON THE YENTILATION or DWELLING-HOUSES & SCHOOLS, ILLUSTRATED BY DIAGRAMS; WITH B8UABKS UPON SANITARY IMPROVEMENTS: BBIN(J IV.- cTOBTANOB OP TWO LECTURES DELIVERED BEFORE THE BOARD OP ARTS AND MANUFACTURES FOR LOWE"' CANADA ; I HENRY H. MILES. Esq., M.A., FBOFBBBOB OS KATHBMATICS AlfD HATUBAIi PHILOSOPFT IX THE UtflVBBSITT OP BISHOP'S COLIiEOB, LBNWOXVILLB, ^rinttU bg Itequeat. S MONTREAL : PUBLI8HBD BY JOHN LOVELL, AT THE CANADA DIEJSCTOEY OFPICH, ST. irlCHOIiAB BTBBET. 1858. " ■il i n*^,. ^ / (^ > r- "rpW!! %r^i^' IX / !.> A w 4. CONTENTS. Paob. Chapthr I.— General observations upon the nature and objects of sanitary measures, 5 II.— On some properties of matter in the gaseous form,. . 19 III. On some physiological and other considerations con- cerned in processes of ventilation, 24 IV.— Some further details relating to the conditions to be satisfied in the ventilating process ; and on simple contrivances for ventilation, 34 v.— On some of the various methods of ventilation ap- plicable to dwelling-houses and schools, 51 CONCLOSION, ^8 ■ Hi PEEPATORY NOTICE. The Committee of the Board of Arts and Manufac- tures for Lower Canada made arrangements for the deli- very of a series of Lectures in the Mechanics' Hall, Montreal, during the winter of 1857-58 ; having selected, amongst other useful and interesting topics, the impor- tant subject of Sanitary Science. The following dis- course was therefore prepared and delivered, at their request, with the assistance of such materials and illub- trative local information as the author happened to have access to at the time. The chief purpose, however, of all the lectures was to present practically useful infor- mation, in as popular a form as possible, so that the subject of Ventilation is here treated of with only such reference to abstract scientific details as appeared to the author absolutely essential to an intelligent dompre- hension of its general nature and objects. The discourse is now printed and published at the instance of several gentlemen, members of the press and others, who imagine that some good may thus result from an endeavor to excite increased attention to mat- ters much neglected in the community, though of deep importance to its well-being. ■igtff'iitt^rii'^'-''^^-'^^^^^^"^^'^"*"^'" ]E. im '■ < " VElSTTILi^LTION ind Manufac- 8 for the deli- shanics' Hall, kving selected, cs, the impor- ibllowing dis- ered, at their rials and illub- pened to have e, however, of Y useful infor- le, so that the vith only such 8 appeared to [igent dompre- blished at the i" the press and ay thus result jntion to mat- ;hough of deep Of DWELLING-HOUSES AND SCHOOLS. CHAPTER I. OBNBRAL OB8KRVATION8 UPON THE NATURK AND OBJECTS OF SANITARY MEA8URK8. Amongst the applications of labour and ingenuity in the coni- laon concerns of life, none present stronger claims upon our atten- tion than those which are specially devoted to the prevention and mitigation of human suffering. Such purposes as these, indeed, enter more or less directly as ends to be secured in most under- takings ; for even men's various callings and professions may be said to be founded, in some measure, upon the necessity of coping with the evils of their earthly condition. But I wouU desire here to be understood as referr.ng to that extensive class of evils proceeding from purely physical causes — inseparable accompaniments of the growth of every community — which, it is believed, become unnecessarily, through neglect and want of adequate precaution, the occasion of a vast amount of the misery witnessed in the world. Some progress has undoubtedly been made of late years towards resisting the operation of such causes by a more systematic intro- duction of what are termed "Sanitary Measures" in the cities and 83f»p><»S(SK»^3SiB■SJ?^?»»Sv»• populous districts of most civilized countries. Yet it is to be feared that we are far from having arrived at a perception of their real nature, objects, and value, so as thoroughly to realize their necessity, or to establish that hearty and general concern which can alone secure their efficient carrying out. Considerations of a purely scientific nature would of themselves suggest the need of precautions for the defence of health. But, as regards people in general, the lessons of science— especially those of Chemistry and Physiology, so much concerned in our present subject— are inculcated in vain. Sad experience, then, both in the Old World and in tho New, proves in the end to be the chief incentive to activity in the right direction. For those who have made sanitary improvements the subject of particular study— the medical profession, statistical writers, Sanitary Com- missioners, Boards of Health, and scientific men in general— con- cur in bearing testimony to the indifference with which the public at large have commonly regarded these matters. It is, as already hinted, only when some great pestilence, as the Cholera, has plainly begun to signalize its access by fatal proofe, that the feelings of people can be warmly excited in their behalf. Whatever the cause of this may be, we cannot agree with those who ascribe it wholly to ignorance. Men are often found, both ignorant and educated, who do not employ defensive means placed at their disposal, even when they well know that danger threatens. Take, for example, the case of workmen in coal-mines, when they neglect the use of the Safety iamp,- sometimes even exposing the flame merely for the purpose of lighting their pipes. Take, again, an instance not uncommon before the more general intro- duction of Dr. Snow Harris's arrangements for protecting sea- going vessels from the effects of lightning i ships returning to port after encountering the hazards of numerous thunder-storms, whose officers made no trial of the complete sets of defensive apparatus with which they were furnished,— the very boxes in which they were stowed away on board having never been opened. Of the phase of human character to which allusion is now made, every observant person's own experience would suggest examples more or less striking. As regards sanitary precautions, it may indeed, in part, proceed from a want of knowledge of the L it it is to be aption of their J realize their joncern which I of themselves health. But, ce — especially ncerned in our perience, then, the end to be on. For those ct of particular Sanitary Com- 1 general — con- 'hich the public It is, as already lera, has plainly the feelings of igree with those 'ten found, both ire means placed anger threatens, ines, when they i even exposing ir pipes. Take, re general intro- protecting sea- returning to port er-storms, whose ensive apparatus s in which they pened. allusion is now e would suggest tary precautions* knowledge of the facta concerned and the scientific principles involved. But it is unquestionably in a great measure due to, and sustained l)y, a feeling that the consequences of neglect are not inevitable ; and there is also the well-known disinclination to take any trouble which circumstances do not appear to render imperative. Such as it is, however, the apathy roforred to has proved a very great hindrance to the progress of sanitary improvements ; and has, ac- cordingly, been a fruitful source of complaint from those who have advocated them. As preliminary to a discussion upon Ventilation, it would be useful to review the whole subject of sanitary undertakings, amongst which it enters as, perhaps, the chief of the processes recommended by science and experience for adoption throughout the community. We should thus, however, find ourselves called upon to notice topics too extensive and too various, and, it may be added, too important, to admit of their being profitably dis- posed of within limits at all consistent with our present purpose. We can only refer in a cursory manner, by way of introduction, to a few leading features ; a glance at which may, as I trust, assist us in forming correct notions of the particular subject before us. Good health, next to morality founiarm of i»eU- ly be discon- )ftble iieij;lei:t ientr of in- and that of dition of ad- tbr iDstHnce, ici hbouring ru are noces- f the inferior iouR diseases pox, Typhus, the centres eet, from the the industri- lurseriea and st all classes, tilar inquiries r the state of conclusively nee alone for y preventible tary arrange- at least on a } community. ssful without all. :> which allu- selves, we are istical return* r to our own lures hare pro- ults as respects Law Commia- n for Inquiring :s, published in leM perfBct records, and to indications patent to every man's ob- servation, to become assured of the existence of a vast amount of bad health. Let us rcaort to the labt Canadian census, by which it is jilainly shown that the proportional number of deaths is ffreater/or cities and populous districts, and that the ratio of mor- tality \& fearfully large for the earliest periods of life. A TABLB SHEWING THE POPULATION AND MORTALITY OP CANADA IN THE YE VR 1851. All Canada, Country Districts, . Town Districts, . . . POPULATION. 1,842,266 1,678,184 164,111 DBATUS AT ALL AOIS. 19,449 or 1 in 94 1.'5,'739 or 1 in 107 3710 or 1 in 44 INFANT MOBTALITT. 9339 • under 6 years of age. 7273 * under 6 years of age. 2066 • under 6 years of age. A TABLB SHEWING THB POPULATION AND MORTALITY i>it CANADIAN CITIES IN THB YEAR 1851. POPULATION. DBATHS AT ALL A08S. Montreal 57,715 1725 \ in 34 living Quebec, 42,052 10G4 1 in 39 " Toronto 30,775 474 1 in 65 " Hamilton, .... 14,112 172 1 in 8" " Kingston, 11,697 185 1 in 63 " Ottawa, 7,760 90 1 in 86 " INFANT MOBTALlTY. > 859 under 6 yra. of age. 734 " " t 245 " " 104 " " 81 " " 43 " " ■• It will be seen from these numbers that the deaths of children un- der ^ue made up Aa(/'the mortality, and even more than that in the case of the cities. t This excessive mortality among children, registered for Quebec fbr 1851, can perhaps only be accounted for by referring it in part to the prevalence (temporarily) of local epidemics affecting infants. Doubt- less a large number of the deaths returned were those of emigrants soon after their arrival. It was not found convenient to procure a distinct return for the fixed population of the city. iO I w. It is admitted that these returns are imperfect on the very points now under notice, but the general facts are manifested clearly enough.* • Some results deduced and calculated from the published returns of other countries, are here appended for the sake of general comparison and further illustration : — I Infant mortality. I„ v,». nf r.n«.nna ATiUuftl Number of cliiliU^ («T (SlOObo?nrX mortality, loolwrn) who die before '°"f 70 veare 5 years of ago. 1 na^n 1 ji.»> ■>• All England and Wales " Town districts " Country districts. . London, (average) .... Healthy quarters. . . . Unhealthy quarters . Liverpool, (average) . , Heal thy quarters.... Unhealthy quarters Manchester, (average) Heal thy quarters... Unhealthy quarters Leeds, (average) Healthy quarters . . . Unhealthy quarters Birmingham Massachusetts, U. S., itverage T.>wn8 Unhealthy quarters Edinburgh.. Glasgow ...-.., Aberdeen France Paris Prussia Berlin Austria Vienna Madrid Rome Sierra Leone 1 in 46 1 in 38 I" in 55 1 inSfl 1 in 46 lin30 1 in 29 1 in 41 1 in 25 1 in 31 1 in 44 1 in 26 1 in 38 1 in 42 1 in 23 1 in 38 1 in 54 1 in 47 in 30 in 36 in 31 in 51 in 42 in 32 in 37 in 34 in 32 lin22i 1 in 29 1 in 25 48 in 100 All the above results deserve the most careful notice of all who have it in their power to promote the introduction and pt ogress of sanitary improvements. The amount of mortality, as expressed by the numbers given, may also be assumed to furnisB, in a general way, the relative extent to which disease prevails ; the fatal cases being, of course, far less numerous than those which are not so. As respects the compara- _1 11 311 the very manifeBted ed returna of ,1 comparison mber of persons of 100 born) who each 70 years. 14 9 20 10 8 81 1 S 24 t of all who hare ;res8 of sanitary by the numbers ray, the relative I, of course, far Its the compara- Aiu-ihtT very noticeable fact is the enormous quantity ot'i.atent, or, as they are sometimes called, quack medicines now used in the commuiiily. Many of these, probably most of them, are taken in different varieties of mahuly, and in various stages of the same disease, and in doses which, it is to be feared, are but too commonly prescribed under the impulse of a wholesale cupidity. It is easy to see that they often become, in the hands of those who habitu- ally employ them, mere weapons of offence against the laws of health. But it is impossible, perhaps, to suggest even an estimate of the extent to which recourse is thus irregularly had to remedies of this class. We know, however, that the consumption must be enormous. They are caMed for from all the chemists and drua- gists, as well as from tlie general dealeis throughout the land. Witness also the pwfuse amount of agency, and of advertising in rewspapers, pamp ', and almanacs, which are sustained by the revenues of those wuo thus appeal to the ailments of a credulous public. From such, amongst other sources of information, we are en- titled to infer that bad health is very prevalent; not to speak of minor evils, such as mere discomfort, restlessness, languor, ill-hu- mour, unrefreshing sleep, and a thousand other indefinite proofs of the absence of a vigorous bodily condition. Now, although medical science has not furnished any satisfac- tory explanation of the modes by which various particular mala- dies are induced and propagated, yet we do know tha the avoid- ance of many kinds of disease is possible through the use of pre- cautionary measures. Experience has also shewn that disorders generally, whether infectious or otherwise, can be modified, their tive salubrity of town and country districts, and the consequent influ- ence on the physical capabilities of the people, we may take notice of the fact, that recruiting officers in England invariably pick the best and largest number of their soldiers from the rural districts. Military me- dical men also are well aware of the superior powers of endurance of men recruited in the agricultural parts, when compared with recruits from London, Birmingham. Leeds, &c. t The numbers in this column afford data for forming a general idea of the relative duration of life in town and country districts, as affected by causes existent at the period when the returns, from which they are deduced, were made up. Imimsi^!mi'ima»iem>>simm«iimmsimn <( To this end it is not merely neceesary that we should an- nounce the momentouB truths "brought to light by our painful inquiries, but that we should insist upon them; that we should repeat line upon line, and precept upon precept, until even the most indifferent is aroused or softened, and a passive assent becomes an active living principle. No great truth was ever inculcated by being once said, and we are resolved to adhere to this momentous question until it has awakened that atten- tion and activity which must result in eflfeotual reformation."— .4r«ron, on the Health of the Working Classes in large Towns. See also note on page 9. , 1. u t In most large towns, it is to be noticed, there are what have been termed A«rt/% quarters and unhealtky quarters,-the distinction having arisen from the greater frequency of disease and death in some localities- The unhealthy districts are usually those which are older, abounding in narrow streets, lanes, and alleys, nearer to the banks of canals or rivers, and situated at lower levels, so that of course the general drainage finds its outlets and termini amongst them, while in many cases they are lia- ble to periodical inundations. Improvements with a view to greater salubrity are often well nigh inpossible, on account of the vast destruc- tion of property and other expenses that would attend the taking of any redly effectual steps. The wealthier merchants and professional men can, it is true, secure for themselves and families, some degree of immunity from the resulting evils by erecting habitations on more elevated and distant sites, and in this manner, frequently arise the distinctions of Nev^ Town and Old Town, so common in Europe, as appertaining to contiguous portions of the same "' Less than 20 years since an able writer, referring to Edinburgh, ex- pressed himself, " It has tl-<> reputation of being a beautiful and singu- larly well-placed city, and has been termed the modern Athens. But this description only applies to the New Town, which has grown up within a century ; whereas the Old Town consists of numerous closes, or wynd>, diverging from High Soreet, and the houses are often 8o close to- gether, that persons may step from the window of one house to that of the house opposite,-so high that the light can scarcely penetrate the court beneath. In this part there are neither sewers nor any private 13 iJ * In the jeings an nil- jris for tlm ites, streets, provided for Tge towns, f we should an- nful inquiries^ jeat line upon ent is aroused )rinciple. No e are resolved ed that atten- •n." — Artizan, ee also note on hat have been inction having ome localities. , abounding in inals or rivers, . drainage finds ;s they are li»- iew to greater B vast destruc- 3 taking of any is true, secure m the resulting nt sites, and in » and Old Town, ions of the same Edinburgh, ex- tiful and singu- 1 Athens. But has grown up eroua closes, or rten so close to- ouse to that of y penetrate the ttor any private For this reason, if for no other, their case ought (o be liel.1 up on all occasions as a warning to profit by in all the flourishing locali- ties of America, which may appear likely to become great centres of population, industry, and commerce. On the principles of liu- manity and self-interest, conjointly, it becomes a duty to conjure all persons of intelligence, property, and influence in such locali- ties, to leave no exertions unemployed, that may tend to secure exemption from similar physical evils. In America, however, even in towns that have already attains 1 some magnitude, the carrying out of eff"ective sanitary provisions, is far more easily attainable than in the towns and cities of Europe. If we possess less of superfluous weahh to invest in the requisite works, we are, at least, not obstructed by the presence of a vast growth of population. We are not, as in Europe, impeded by a natural disinclination to meddle with habits and places and structures hedged round by historical reminiscences or consecrated by venerable antiquity. Take the example of London, which in former times was remarkable for the entire absence of sanitary precautions, the streets many feet below their present levels, irre- gular, crooked, and narrow, so that people on opposite sides could conveniences whatever belonging to the houses ; and hence the refuse occasioned by the presence of at least 50,000 persons ia, during the night, thrown into the gutters, producing, in spite of the scavengers- daily labours, a state of things extremely prejudicial to health. Can it be wondered at that, in such localities, health, morals, and common de- cency should be at once neglected 7 All who know the private condi- tion ot the inhabitants will bear testimony to the immense amount of their disease, misery, and demoralization." Mr. Chambers, in a letter to the Poor Law Commissioners, observes of them, " They have gravitated to a point of wretchedness from which no efforts of the pulpit, the press, or the schoolmaster, can raise them, for they are far too deeply sunk in physical distress, and far too obtuse in their moral perceptions, to desire advantage from any such means of amelioration." Dr. Alison, in his work on " The Management of the Poor iu Scotland," says, " The lodgings, houses, and closes of the Old Town are scarcely ever' free from malignant fever ; and, in the city iteelf, the mortality in a single year has been as high as H per cent, (or 1 in 22). Nothing short of a pretty extensive demolition of the Old Town will stay the evU." 16 shake hands with each other. The resulting evils had reached a great height by the middle of the l7th century, without any geri- 0U8 efforts being made for their removal, bo that in the end it was reserved for the great fire &iidplaffue of 1666 to pave the way for and inaugurate the enforcement of some sanitary measures. It is proba- ble that no other imaginable means than such signal calamities could have served to vindicate the laws of public health. Even in our Canadian towns, conflicting local interests, and a dread of the expense necessarily attendant upon the execution of works for sanitary purposes, are not uiifrequently permitted to hinder their adoption or their progress. Of the consequences, the history of sanitary undertakings elsewhere, furnishes many sad ex- amples. We learn that delay in endeavouring to grapple with and to vanquish these and the like difficul*ies at once, may amount only to staving them oflF until they entail upon ourselves or our successors evils impossible to be endured. Take again a single example from the case of London, where, at the present moment, measures are in hand for preventing the utter contamination of the Thames water. This result, proceeding from an imperfect system of drainage, was foreseen many years' ago ; but to those, who have at this day to cope with it, the trouble and cost have become comparatively gigantic. One estimate after another has been suggested, until the anticipated expenditure has reached to upwards of twenty millions of dollars. It is as if the city of Mon- treal were now required to be taxed half a million of dollars in order to pay for the neglect to lay out a few thousands forty years ago. Enough, perhaps, has been said to illustrate the general purpose of sanitary improvements ; but if we examine tte subject a little further, and with reference to particulars concerned in tlie practi- cal execution of any system, this will be found to resolve itself ultimately into the carrying on of a species of warfare with the properties of noxious gases. Solid and fluid materials capable of evolving these— especially decaying animal ard vegetable pro- ducts — are required to be withdrawn from our vicinity, lest by exposure to the sun or atmosphere, they become sources of ex- halations injurious to health. All kinds of refuse matter, in fact, must, on that account, be prevented from accumulating in the 17 ad reached a lout any seri- he end it was lewayfoi'aud It is pioba- .al calamities ilth. ierests, and a execution of permitted to equences, the many sad ex- grapple with , may amount selves or our gain a single sent moment, taminatioD of an imperfect but to those, ind cost have r another has is reached to i city of Mon- I of dollars in ids forty years eneral purpose nbject a little in the practi- resolve itself rfare with the als capable of vegetable pro- cinity, lest by sources of ex- nattor, in fact, ulating iu the streets, or in and about our habitations, whether they originate in carrying on processes in the arts or manufactures, or in the proceedings of daily domestic life. For a like reason, even water which has descended from the clouds, or which may have re mained behind after the subsidence of an inundation, cannot be suffered to remain stagnant ; for if not quickly removed, through artificially constructed channels or otherwise, its evaporation serves as a vehicle both for diffusing a hurtful dampness, and for spread- ing through the air we breathe many unwholesome substances which it previously held in solution. The requirements, therefore, of a considerable town create a necessity for adequate sewerage, together with abundant and con- tinuous supplies of pure water, as well for all detergent purposes* as for absorbing and carrying off all products that might by de- composition originate such emanations as have been mentioned. Then there is to be dealt with an unceasing and prodigious flow of poisonous vapours, arising from combustion, from the respira- tion of living beings, and exhalation from the surface of their bodies. To devise plans for establishing such arrangements, to execute them, and to adjust the general system to the wants and pecu- liarities of every street and every individual habitation, to cecure • The purposes here indicated as objects on account of wliicii an adequate system o{ wUer-works is required to be oatablished in every town, village, and habitation, are not bo generally appreciated as they would be if the unnecessary waste of human life were regarded i«'ivh the same hearty concern as the destruction of property by calamitous fires. Yet it may be asserted, that the actual loss occasioned by the latter is not nearly equal to the sum total of what society at large suffers from the neglect to supply water copiouily, at any cott. With that essential tributary to the means of purification, conveniently furnished in all our streets, lanes, and honses, the community might save much that is now ex- pended in other wayu, — in sustaining various institutions, medical and others, — in repressing crime, — in supporting or assisting the destitute survivors of those who perish prematurely. Who can pretend to esti- mate the mere pecuniary loss annually inflicted by the unnecessary abridgement of valuable lives, or through the unnecessary impairing of those energies in thousands upon which depend the useful exercise of labour, skill, and intellect in the various callings 7 ■"Wl fetai,.,, " It such wnivftrsal co-operation and attention to details as are requi- site to their ftill Bucoees, and, finally, to reconcile men's minds to the outlay needful, which can only follow upon an established conriction of its necessity,— constHute, in all, one of the mostim- portant and complicated proWems of our times. MiirtBHi*>ii' 1» CHAPTER IIv 6k BOMK of THK PR0PBRTIB8 OF MATTER 111 THK gt cracks or ; porous snb- ister of Paris. referenee to 1 processes of a compara- tbe idea that c acid) into a Id not, in the id, or at least parts. Thus, immediately tt^ imporfant Also, especially in a physiological point of view, and in connection'with the subject of ventilation, to note particu- larly fhia etnrkpaktlive facility, or rather the rapidity, with which matter in £hd ^ftsJous form findt its way to and acts upon the sourtet 6/ vital potoer. The most familiar instance, perhaps, is that furnialiedft/the inhalation of tobacco fumes. Opium also, iodine i mireury,knd a great many other substances, when ren- dered vaporou* !S^ heat, are found to affect the animal functions far more Yapidl^than the same bodies when introduced into the BVstem in flieii' Cfcstomary solid or liquid forms. Ether and rhlo- roforin may alsJb be mentioned, now so extensively employed in niedicineni CAsev where it is an object to produce a speedy insen- libiHty to. pain.' ' licit we havft^'tr possible, still more decisive proofs in the in- halati6n*bfga8ei whose effects are deleterious, the most remark- able- being compounds of hydrogen. ; \ Artmietted hydrogen (formed when an alloy of ztnc and the metal (O-ienic is submitted to the action of acidulated water) quickly causes death when breathed in the minutest quantity. Sulphur elted'hydrogen* in like manner is very potent. It is ektinguishes it. Again, carbonic acid gas is sometimes found nearly pure in olit wells, ic. ; and in certoin cases possibly the air in the lower J)Mt« of a; buUdiiig used for public assemblies may become sensibly tinted before tfee effect has become oppressively disagreeable in he glfllerfes, In the Absence of ventilation. In the two latter cases, how- itii'l ift ii to be recollected that the carbonic acid is in continual pro- "^^i^ of generatiJte, while time is required for the compleu -llffusion referred to in the iext. It is quite natural to expect that the moi ira- '^e^lijto effect? of the noxious gas should be encountered at and near to Wl^i^Wi orln itose parts into which it enters in a mass through the tiiteiaictibi of gravity, as in the case of the extinction of the lighted Mfjiti, lii Tact, that is here contended for as worthy of particular :iiistiee In cofliiexlon with the subject of Ventilation,' is, the established -^f^lpUtf dilution throughout each other's substance whenever hetero- **]j{*ii«MM »*»»* tere^present and in communication with each other. ^jpl^'f^^etm ifc tW principal gas rising iVom drains, cesspools, Ac. To prove ■ ""^ cfes&uCtive qfltallties, it has been injected into the veins and chest and iiWftH'ttieakVjij)f animals. Two or three cubic inches employed in tbfs wax were f6§nd to destroy smaller creatures, as cats, rabbits, *c., vuiaAtly: A raTiSitwas Immersed in sulphuretted hydrogen to the neck, r 1 22 Mid that air •onlpning sulphuretted hydrogen to the extent of l-800th part •ofbw to kill a dog, and Umt when l-2o0th part is breathed by a horse, even this large animal »o<.>n an o. unbs. Car- Imretted hydrogtn* also is another very deleterious gas when taken into the am ••*! system. Of carbonic omV frequent mention ia made in the . lowing pages as being produced whenever the pro- cesses of combustion and respiration Uke place. Its effects are immediaUly injurious, aad the amount of injury cauaed is pro- portional to the eitent of its admixture with the air breathed. Now when we conmder the peculiarities of gaseous bodies which have been mentioned, their iiwtsiNKly, their tpontomouily dif- fudve power, and their Jjxerfy «<»«♦ »P0» ow bodily organtsa- tion, we cannot fiiil to perceive the risks we rnn whenoTirr we neglect to adopt such njeasures as may be reqnisit* ia oidw. to liBcure their absence fro m our vicinityf. W e must see that wo are •nd died tn ten n..Qut«, thougrh allowed to breathe tli* pare atmoi- phere. Nine quarts oi tke gas we«e injeeted into the lateetinM of a horse, and the animal fell dead in one minuii. Children and even adults have frequently hXlen victims to this poAsououi snbetonce on the ooca- ■ioD of drains being ineautlously or aooldentally opsned. Breathed in a ■t»te of dilution It is excewively injurious to health. • This gfa is produced In our stoves, and also when common eoal Is burned. U Is lighter thun air at the same temperature. On the animal ^system, when inhaled, it produces Immediate sensations of $hejiint$i, sccompanled with extreme aense of weakness. In DugliosoB's Phyfl- ' Ology It Is BtaUd, " It is very depreasing to the viul functions. Iren When largely diluted with atmospberie air, It occasions vertigo, si.ek- iMS, diminution of the fores and velocity of the pulse, redqctioa of oiuscular vigor, and every symptom of diminished power." t It may not be out of place here to allude to the absorbent power possessed by bodies, solid and liquid, In virtue of which a gaa is some- times enabled to permeate their snbtUnee. Our foo^ and drink may thus imbibe hurtflil qualities from mere exposure to unwholesome ^r. The eflbcts upon milk, butter, meat, bread, *e., are well known, being •oon appreciable from the changes of flavour produced. Our clothing, too, articles of merchandise, *c., are in liVe manner susceptible of bejng rendered the Tehicles of deleterious ir ' > & !r^«af ^fneea of contagious maladies mix/, by their means, be traDspOi'. n ft'.-, place to pJ- cs. In some important swt»»J P">e*«^'°tr * " ""' 1 so difficu.v .0 dis- lodge the morbific agents thus iutroouceu uum beyond the sea, that re- course is occasionally had to the destruction of property of value, lest It should become a source of wide-spread disease. lie extent of ;50th part i» imbi. Cur- s «rhen taken t mention is leror the pro- ts effects are iu»ed is pro- breathed, bodies which t0nt(m$lv dif- lily organ! %»- vhenoTirr we i in uiU«i t<* >e that wri are « pare atatoi- intMiioM of a ind eren adultt e ou the occ»> Bna|h«d in a omnoB eoal it Oa the animal It of tltepinti$, ^ioaoa's Pay»l- netioBS. Sren B rertigo, siek- e, reditetioa of iMorbent power h a gas is toine- •nd drink majr iwholesome a{r. II known, being Oar clothing, wptibleofbeiag es of contagions ,ce to pi' C8. In • difficu.i ii> dia- the sea, that re- r of ralne, lest it •S surroundod by tDtli>nnceagriuveuHly inimical to health whenever we suffer ourselvea to remain in siJuations where we are obli'itd to in' letheiii Yet such i, always the case whenevor we o- luntarily remaiu in confined apartments; whenever we do not provide specially for the in^reu of freah air and the eaoape of that which has been vitiated. As I shall have oooasion U; refer to these things several times further on, I shall only add here that the wonder is so many of us escape so long with comparative im- punity, when we reflect upon the continuous charact- r of the sources of impurity amidst whieh so many of us are content to pass oar lives. If sulphuretted hydrogen and carbonic acid gas be really injurious to health, and in cei tain cases destructive of life, then surely it becomes worth our while to cherish at all times in our minds a lively appreciation of the fact that these very gaees are ever present to afflict ns, and that they will afflict us unlm m take measitreg exprtutyfor pre»erving the purily of the frir we breathe. They are not only evolved copiously in our streets from drains, cellart, A;c., but they also emanate froi most forms of decaying vegetable and animal matter. Thcv e produced within our own bodies, in our stoves and fireplaces, a d, in short, ■wherever the processes of life and combustion go on. *^ There have been mentioned only a few of the pi nerties of gMesj—of those more prominently concerned In our prese t inquiry. But there are, as may be supposed, various other qt alities, a notice of which would apperUfa to the subject. It woui \ be well H, tat instance, we could here ttH forth the foots relating to Uie mechanical and chemical characters of the more common gaseous bodies, especiafly atmospherU air, carbonic atid, and natery vapour. The laws of gaseous motion, the laws of their ►^rpan- non by means of heat, and also with reference to hygr Tietric .»nd electrical conditions. A ftill consideration of these ings, ^'-iiowever, would scarcely accord with the requiremenU of a opn- «kr discourse ; though the want will be found to be, ii. some mea- sure, supplied by tho tabular Statements and brief incidental n 'ces .which occur afterwards. 24 CHAPTER III. ON SOME PHT8I0L0GI0AL AND OTHER CONSIDKRATI0N8 OOH- CBRNSD IK PR00ES8S8 OF VENTILATION. ;■ c. , '■ It appears that the fabric of the human body is dependent for tJje healthful action of all its organs, and for the maintenance of li.e itself, upon the continuous supply of nutriment to every part oi" the system, as well as the continuous removal of various effete or refuse ingredients generated within it The transfer of the materials of nutrition throughout, after they have undergone the digestive action, and an important part of the duty cf draining off, as it were, products no longer useful, or such as have resulted from various internal processes, are performed by means of the circula- tion of the blood. Constituting about one eighth or one ninth of the entire ponderable substance of the body, it may be conceived to receive its 6nward impulse from one set of vessels in the heart, through the arteries, towards the remotest extremities of the sys- tem, whence it returns again in the veins to be propelled by ano- ther set of vessels towards the lungs, from which it retires to it« former place of departure, to be again sent forth as before. >The movement never ceases for an instant during the longest life. In its course from the heart, the blood receives into its current the materials for nutriment dropped into it from appropriate vessels . communicating with the digestive organs; which latter are them- selves sustained in activity and health by what they derive through other vessels from the great circulating medium. At the lungs, the matter of the blood is, as it were, thinned out in contact with the interior membranous surfaces or walls* of myriads of cel)ul»r spaces, which constitute together the chief volume of the lungs, and are placed in groups, of many thousands in each, around the ends of what are technically termed the hro^ichi. The Bronchi • It has been calculated that »b many as It.TOO air-cells are distri- buted about the end of each terminal bronchus, and that the total num- ber of cells is not less than 600 millions. mii WOKS oou- r. lependent for ainteuanoe of to every part various effete ransfer of the indergone the •f draining off, 1 respited from jf the circula- r one ninth of be conceived 3 in the heart, ies of the sys- pelled by ano- t retires to its i before! *T0he ogest life. In its current the opriate vessels itter are them- lorive through At the lungs, a contact with ads of cellular 9 uf the lungs, sfa, aruund the The Bronchi -cells are diitri- t the total nnm- 25 communicate in tubular passages with ihc trachea or windpipe, tbrougli which the at(tiospheri(i air is inhaled from without, and thds broughl. intb contact Vrlh ttie surfaces of the a,bove»inen- tion.ed'cells, but on an oppbsiie i'slde, so^ that an indefinitely thin membrane intervened between the blooa^and the air. In confor- mity with a law of gaseous actidn, noticed in ^he preceding chap- ter, gases are thus enabled to paM from the Blood outwards, &nd from the atmosphere ihwards.' In fact tBe actual result of the respiratory proces%'i8, thStatTe^fe^ insptfatipn of air through the windpipe a portioa jol iS oxi/ffeh pa^es by diffusion into the blood; while at every ea^nraiion, gasapus matter, previously in tiie blood, is ejected through the same channel, together with the air thus altered by the partial, absorption of one of its essential ingredients. The expiratory ict is attended with an accompany- ing surplus of watery vapour, gen«((»lly toore or less charged with particles of animal substance derived from the ^pjsteDed co^iftg of the lungs, throat, and fauces. $n tjiis maqaer, and at the rate of twenty or more times a minute, sap^li^ of oxygen gas are in- troduced into the system ; and at the, same rate, products neces- sary to be re»»ioved from within find an outlet By the process, thus familiarly* described, the blood is under- stood to suffer important changes at the instar t of its anival from the heart into the lungs/ But it is believed that the greater por- tion of the oxygen absorbed is carried' bodily in the circulatici. to all parts of the fabric; beiiig distributed, as required, mmlpute quantities, until, by the time any given portiOttfof blood' returns to the lungs, the free oxygen has disappearedi and the circulating fluid iUelf is charged with the products already referred to. One chief use of the oxygen is undeistood to be the consumptiou of animal tissue, and of the mfnute vesicles and organs by which" the internal functions are performed, but which bse their vitality, in the act, their substance combining with the gas lo as to form carbonic acid, and in part creating and sustaining the animal heat through the combustive process incessantly kept up by its instru- mentality. By referring to the tabular statements, gjven at the • it is tHbught tl^t the "present ptfrposesW description are best served by avoiding as much as possible the use o^technical terms and bycom- Bulting brevity. 86 close of this section, it will be seen more precisely what quantities of atmospheric air^ oxygen, nitrogen, carbonic acid gas, and watery vapour, are concerned in the exercise of the function of respira- tion, and also the extent to which the contiguous air is liable to be rendered unfit for breathing by each respiratory act. Resuming, for a moment, the subject of the Circulation, it may be summarily repeated that its appointed function is four-fold. Ill *^he first place, it transports, through appropriate channels, to all parts of the body, the materials for structure, — the various tissues having the power of absorbing from this liquid the particular eom- ponents of their substance. Secondly. The circulation answers the purpose of carrying off, in the current of tho blood, all the products of ^ecay of the various tissues, and the different excretory maitters which are set free in the course of the nutrient operations,— carrying these to thar proper outlets, partly to the akin,* but chi^y to the lungs. ^.,,Thirdly. The circulation serves as the means of introdiiciag oxygen gas into the system, the union of which, witl ti«3 caihon of the tissues and fluids of the body, produces carbonic cteid, elim- inatedf as described above. • The matwrials emitted every minute by cntaneons exhalation are foand to weigh from 9 gn. to 26 gn., and consist of aqaeoas vapour mingled with decomposing antoial substance. t It may hen be remacked, on the best plijaiologieal evidence, that there can be no cessation in the process of elimiaating carbonic aoid, without dtaih ensuing in a very few minutes. When, however, only partial intermissions occur from any cause, or mere hindrance to its continuous evacuation, in the complete manner demanded by the wants of the system, then carbonic acid aocnmulates 'a the blood, and caasoa oneasinesi and indisposition, according to the ctrcumstanoes of the case. Bzperiments have been made npon the eCfocts of external heat and cold, and of the presence of an excess of carbonic acid in the external air, with a view to ascertain, how &r the eliminating procesf is faoUiUted or obstructed by each causes. Uessrs. Allen and Pepys, among others who might be referred to, after a series of elaborate inves- tigations, detetmined that the presence of even a minute excess of oar- %onia aoid in the sdr breathed, interferes materially with iU excretion from the biood through the lungs. But the effect of cold, is to aug- ment the emounkdisohaiged ; hence may be inferred the resulting injury to health, when the demand for excretion of carbonic add ia rendered m m what quantities gas, and watery :tion of respira- i air IB liable to f act. lulation, it may on is four-fold. I channels, to all a various tissues I particular eom- I of carrying off, ay of the various \ are set free in f these to i\mt ihe lungs- i of introducing (fill uti caibon bonie acid, elim- 08 exhalation are )f aqaeons vapour eal evidence, that ag carbonic add, m, however, only I hindrance to Its aded by tbe wants blood, and eanses itances of the case, ixteraal boat and sid in tbe external nating proceir is Allen and Pepys, of elaborate inves- nute excess of oar-< with its excretion )f cold, is to ang- ihe resulting injury c add is rendered VI Fourthly. The blood thus transport the means of generating, and diffuses the animal heal, — or at least is understood to be the principal agent in the procesb. Of the function oidigettion, it does not seem absolutely neces- sary to occupy time in particular description. It may suflBce for our present purpose to state, summarily, that the three great physio- logical operations of respiration, circulation of the blood, and digestion, are each tributary to the healthy continuance of the other,— and so bound up with each other, that the cessation of any one is necessarily contemporaneous with that of all : and finally, as respects the circulation, if, through any cause, a sufficient supply of oxygen gas is not furnished through the lungs from without, or if deleterious gasses be inhaled through the windpipe, and thence partially imbibed by the blood at the lungs, then every fibre, tissue, and organ within the body,— the nerves, the brain,* the heart, the stomach, the lungs, and the Wood itself, are subject- ed to immediate injury .f The result may be mere inconvenience, or it may be disease, or, in extreme oases, death. A little attention to the foregoing particulars, and a reference to those which are stated in tabular form at the close of this section, would convince any reflecting person how desirable it is, how necessary to the preservation of good health and bodily comfort, to provide effectually for the two-fold purpose of "Ven- tilation." Whatever the particular processes may be which are adopted for its accomplishment,— whateverthecost, — wemustboth have the pure atmospheric element to breathe, and also be fireiBd frOTO the presence of vitiated air and of all gaseous matter unfit for respiration. The products of respiration, leaving the body at a temperature of about 90*» Fah., and those of combustion, passing from their eourees at a much higher temperature, naturally move upwards, in obedience to Uie force impressed upon them by the heavier surrounding medium. But as they vitiate the latter in greater than usual by one external eanse, and the capability of exerols* iog the function, if, at the same time, diminished by another. • It is oaiculated that about one tixtk par*, of the whob blood is trans- ferred direct foom tbe heart to the bnain. t Tbe rate of curcnlation is ostimated at ISO utandt, or leas than 3 mkwtet, for each oompkte round. ^8 much larger volume than their own, anid^oh cooling, as well as by the piinciple of diffusion, are likely to come down ag lin and spread around us when we are within ^aprs, in our houses, whore those products are continually in process of formation, wo can never feel free from the danger of inhaling them again, unless special means are provided for their constant removal and ejection into the atmosphere without. , .^ • Jho //»««,' however, of air for reapiratiop doe? not >»holly con- sial; in its purity— it is additionally reqMMte that' it should be at a congenial temperature,* and that it should be neither too dampf nor too dry, to 8uiu'tJ»e4r ofUbt&tioqs erecied, whether under the superintencienoeof their owners or that 'of architects, in which the object receives any attention whatever. As it is intende4 to devote the subsequent section to the congideration of various 'methods which are in use, or which have been suggested, I may ' lie permittpd to occupy the remaining portion of this chapter with some general remarks upon the state of things consequent upon the negh'Ct jnst alluded to. c • The tempcratuw ittost generally aooepUble is about 660 to 70<» Fah. t When the moisture of the ait is e8*l«hat*l by means of two thermo- meters, the amount indieated byik.di/r«refic« of 6° belwe^in the tempera- tures of the dry and wet bulb maybe regarded «w i»t unsuitable— a greater difference than that would b^ ia;amtl8ible'--brit « Ibs's difference would shew tot» much moisture. . 20 g. as well rt9 by iwn ag.iin and ■ houses, whore lation, wo can 1 again, unless iral and ejection not yrholly con- it Sshould be at ither too dampf rhich is implied s important to the ventilatipg- cies of each oc gd aa well for Vd other coincn nod or the air imply the fulfil- A the guariliti/, jether with the s vitiated. The in this country, air such a system. ; whefier niiilcr hitects, in which it is intended to ition of various iggested, I may this chapter with lonsequent upon It eS" to 70«» Fah. ns of two thermo- (ro^n the tempera- ttot unguitable— a rt ■ ks's difference lu our rigorous climate, during several months annually, owing to the prevalent mode of heating, and the disposi- tion of people to shut themselves in with all the assistance that can be derived from the use of double walls, doors, and sashes, to keep out the cold air, we are indebted for what good health we do enjoy, and even for the preservation of our lives, mainly to the imperfections that attend the best workmanship. It has been calculated that about 7 or 8 cubic inches of air pass, per minute, between the junctures of the closest fitting ordinary window-sash, when the difiFerence of interijal Itod external temperature is about. 209* Fall. If we take al^o Tato account the opportunities afibrded along the tops, sides, and bottoms of door«, notto. spe^k of other accidental fissures or openings, we see that, in spjte of ourselves, the oontinuousingress and egress of air, are to. some extent secured. The various kinds of powerful heating apparatus which are in use in this climate, maintain also, the strong drafts necessary to supply the incoining «ir Jo,. in' a. close, peat-np rooia, sickening from ths' smell, w»« the peMeption of closeness will so entirely vaitish, that he will almost tUMj the atmosphere has been purified since his entrance. If then, sueh are the effsots of an hour in blunting our refined sensa- tions, and tendering U»em insensible to noxious exhalations, what must be the influence of years on the perceptions of the working man? All who have the requisite experience wiU testify that the last want felt by th* dirty isdeMUMSf." X 31 r quite eonsitt- (ton, because it t there is most / to think and ue to the cause oUs, incidental rceptible man- chief operat*!'. 8 of becoming i within its in- Q the mornt'ng, vacated, sieep- lation, the biiU tantly obvious. e arising from , almost ceases. of the visit, is me peculiarities )l8, workshops, hvm partially or at the apparent tnessed. Many inhabit decent r 1 • < • ■ r ' • T I by authorities on affioiently urged. UMorily. In tbe England, we find One gentleman let a man remain, ;keBing from tba' [y vanish, thatiM ince his edtrantie, our refined sensa- ktiona, what must irlting man? All ) last want felt by honses and are not remarkable for disregarding obvious claims upon their attention in most of the common concerns of life, are thus undoubtedly under the influence of habitnal adaptation to the consumption of inferior air. In country school-houses, of Eastern Canada especially, where 40 or 60 scholars, and even larger numbers, are often crowded into rooms about 20 feet square, with door and windows closed, and the interior maintained at a tem- perature of upwards of 80o Fah., it is no uncommon thing to notice an entire want of perception of the mephitic character of the air; teachers and taught alike, and visitors too if they re- main some time, uaconaeioosly breathing the same products over and over again. He remarks which have bean made respecting the absence of ventilating arrangements in Canadian houses, refer mainly to the winter season ; at which period, as will be seen, the means of executing them economically, and of regulating them, by contri- vances almost self-acting, are certainly more available than at times when domestic fires are not maintained. During these latter periods — in the summer; for instance, and early autumn — they are at least equally necessary for the preservation of our health, especially in the night time, as well as in such states of the weather, and in such situations, as do not admit of the ordi- nary facilities offered by the use of doors and windows. In short, it may be confidently stated that a system which shall satisfy tJ! the conditions and requirements, under all the varying circum- stances, thai present themselves for aUow«nce, and at all times and seasons, ia a desideratum which is tm from being supplied in.> thit country ; although, undoubtedly some progress is now being made, by which, through the introduction of improved heating arrangements, it may be hoped that the evils notfced will be at least partially remedied. In the following chapter some more practical details will be fornished in relation to the conditions to be satisfied by any sys- tem that can be deemed effectual ; and in tbe< meantame some numerical statements, previously referred to, ate i^)ipended in this place :— 'fa ■-/ ^^^^S™^ifc(iJS«K"-rt#fi^-.>^*i. U. V'.i \ / 32 Table of Rtlative Weighti of certain Gate$. Commonair JOOO "* Oxygen 1111 1? H/d?ogen O.Of ^J NitrogeA..... 0-9^a l* Carbonic acid 1B27 ii Bulphurttted hydrogen.. : M80 i« Carburetted hydrogen » 9'2 14 In the first column of numbera the weight of oxygen ia taken aa the standard for reference ; in the other, that of hydrogen. Con$tituentt of Jitmotpherie Jir. ' 100 parta of air contain,-i- . Oxygen 21 parta nearly (6y wei?At.) Nitrogen ^ " '' Carbonic acid 06 part Watery vapour variable. Table ihomng the Quantitiet of Watery Vapor retained invinbly in the Air, by which it it taturated. Tempcmturo. Saturstins Quantity. ^ 32» Fahrenheit a.3 graina per cubic foot. 'xno " 3 " too « 4.1 " " " . eoo " 6" " " " •". 65° " 8-T " " " ' 11. u 9 " " ' ROO " 10.5 " " " . Iso. « . 12 " " " JSo •' , 14.1 " " " 100° " ^ ^^ According to thia table, and the atatement prevloualy made, air for reapiratiou at 66° Fah. ahould not hold f much aa 5J gra. of water in suspension, thia being the aaturating quautity for 60° Fah. Respiration of Mult t (average retultt). Number of respirationa 20 per minute. Air inhaled at each inspiration 20 cubic inches. Air inhaled per minute 400 cubic inchea. Oxygen inhaled at each inaplrition 4 cubic inchea. OMgen inhaled per minute 80 cubic inchea. f Todudts expired, — (1.) Damaged atmospheric air, with nitrogen in excess. - (2.) About 15 cubic inchea carbonic acid. (3 ) About 3 gra. watery vapour, impregnated with carbonic acid and decaying albuminous animal aubstance. Surrounding air vitiated by mixture with the producU of reap'- ration 2J cubic feet per minute. «;:*i. 14* 15 1 U 22 IT 14 taken aa the r {by toeight.) nvitibly in tAe Quantity, cubic foot. II «< II II II II 11 ly made, air for rs. of water in r minute, bic inches, bic inches, bic inches, bic inches. n in excess. 3d with carbonic . substance, oducts of reap' • r minnte. 89 Retulli of Sir Hnmphrey Davy'i Experiments on himtelf. Oxygen required in 24 hours 45,504 cubic inches. Carbonic acid eliminated in 24 honrs, 3l,C80 cubic inches. Containing of pure carbon 4,853 grains. RttulU of Experimenii by Dr. Southwood Smith on Retpiralion and the Circulation of the Blood, Volume of air ordinarily in the lungs 12 pints. " " received at one inspiration 1 pint. Volume of air inspired during the time of one cir- culation of the blood 48 pints. Blood which flows to the lungs at every action of the heart 2 oances. And which is acted on by the air in less than . . 1 second. Total blood in an adult about 24 lbs. or 20 pts. Oxygen taiken in in 24 hours 33 ounces. Carbonic acid excreted in 24 hours about 18 cubic feet.. Pure carbon expired in 24 hours about 10 ounces. Table ihewing Products of Combuttion of certain Substances, and tht Extent of Action on the Air. Products of combustion of coal, coal gas, and wood Carbonic acid, nitrogen, aque> ous vapour, and carburetted hydrogen. Products of combustion of oil and tallow chiefly Nitrogen, aqueous vapor, and carbonic Acid. Combustion : 1 lb. of coal requires for com- bustion and accompanying waste of uir 200 cubic feet of air. 1 lb. of tallow vitiates . . .about ItO cubic feet of air. 1 cubic foot of comimon coal-gas vitiates about 10 cubic feet of air. And produces about 1 cubic foot carbonic acid. Together with .... about 6t0 grs. of aqueous vapour. Which is enough to satu- rate 100 cub. ft. of lir at 66° Fab. 1 lb. of charcoal consumes all the oxygen in. about 175 cubic feet of air. Vitiating besides ..about 600 cubic feet of air. 34 CnAPTER IV. 80UB rUBTIIEn DITA1L8 RILATINO TO THE C0KD1TI0N8 TO B« BATISFIKD IN TI- K VENTILATING PROCESS; ANB ON BIMPLS C0NTR1VANCE8 TOR VENTILATION. 1 The accomplishment of a ventUating process Las been stated to consist in an adequate provision both for the ingress of rcspir- able air, and the egress of that which has been vitiated or ren- dered unfit for respiration. It is evident that unless the latter object, egress, be secured, neither can the fon.v r. We can no more make air to enter a room without causiu^ *.te exit of gase- ous matter from within, than wo can pour more water into a bottle already filled with that lioa.d. There mu^t be in fact, in obedience to the laws that govern the mobility and equilibrium of the atmosphere itself, a perfect accord between the rates of motion and quantities of the effluent and in-coming gases. Tt is therefore not enough merely to throw open a door or a window, although by so doin;.; the air in a house or room be- comes in time sensibly changcl. An actual movement is needed, consisting in one part of air and gases moving outwards, and in another of the fresh entering air. This is a very important con- dition, and practically one which it is often difficult to secure or to regulate. Connected with it are various other questions of a practical nature ; such as the dimensions and forms of the neces- sary openings, the situations in which they should be made, and the means of adjusting them to the ever-varying occasions for their use. Some of these apparently minor concerns are often dealt witli by those who do attempt to ventilate their tenements, just as if they were to be regarded as mere matters of taste. But unfortu- nately they cannot be so disposed of. They can only be deter- mined upon practically by the instructed architect, or by one who is at least conversant with the laws of gaseous action and the other scientific principles involved. .,o#- [TI0N8 TO BX in OK BIMPLB I as been stated tress of respir- 'itiated or ren- tiloss the latter We can no le exit of gase- ! water into a , be in fact, in id equilibrium n ibe rates of a a door or a ise or room be- ment is needed, itwards, and in important con- t to secure or to questions of a ns of the neces- 1 bo made, and ng occasions for )ften dealt with tient9,just as if 3. But unfortu- only be deter- tect, or by one seoua act ion and 98 It 18 also obvious that the dimensions of the openings required for ingress and escape, the forms of the conducting channels, the velocities and the quantities of the moving gases, must bo all connected with and nintiially dependent upon each other. Wc see, therefore, that these things become the subjects of numerical calculation based upon physical laws, which may not be dispen- sed with if the hope bo entertained of attaining to a perfect sys- tem of ventilation. Now it happens that the laws of gaseous motion as respects the mutual relations of temperature, density, velocity, friction, and the dimensions and forms of the channels, are amongst those parts of science that are least perfectly understood. Theoretical science therefore fails to furnish all the aid that would be re- quired, and it becomes all the more necessary on that account for every one who desires to ventilate his house properly, to con- sult a competent architect as to the best mode of arranging about the above particulars.* • The dimensions of an opening and the velocity of the enteriog or efflu- ent air beitg Icnown, Uie quantity that would pass per minute is of course readily determined by an arithmetical operation. In practice, tho dimen- sions can be measured, and so also can the quantities, though less easily, be estimated, and thence the actual velocities, aud, in the end, the retar- dation from friction. But in practice the determinations thus arrived at in several cases are not found to present a clue to any general law sufficiently precise to be applicable in all, so that approximations only are made to supply the want of certainty. Bxperimenta on a large scale have frequently been made with a view to determining tho rela- tions of dimension, velocity, quantity of effluent gas, friction, and amount of impelling force, but always with variable and uncertain results. In one instance, when the actual quantity of air cencerned was known to be 14,726 cubic feet, the various results calculated from five different recived modes of approximation, were to be obtained from the numbers 18,169, 15,655, 16,162, and 6,017, respectively, upon each of which, the very tame aU»vianee for {Hction being made there would arise corres- ponding discrepancies. It appears ui necessary to go further into such particulars, but I may here allude to formulae and rules given by Tredgold, Sylvester, and others, and also to an easily computed process of M. Montgolfier, employed in common cases, in which these relations become the subject of necessary calculation, and which are understood to furnish tolerably correct ap- proximations, as far as they are needed. ■:^'A ^u mii0^"i J & > m^:)i'i'^ TS 86 As respects the quantity of air required to bo supplied for re»- pirrtfory purposes alone, the statement* wl.ich have alroftdy been ma.le aro pchaps of too general a cliaracler to permit our pas- sing immediately to other topics. Until quite lately, and even now, in the great majority of cases, the practical question has been disposed of by reference solely to that bulk of air which might bo assumed to continue on the whole fit for r.npiratioa during the period of occupancy; as, for instance, to allow bo many cubic feet to each person. In thew cases the authoritative customary quantum has been variously rated at from 800 to 1200 cubic feet, taking for granted that the continuous occupation will not last longer than seven or eight hours without measures being taken to change the air within completely. The lato Sir C. Na- pici— emphatically styled the "soldier's friend" on account of his uniform attention to the wants and comforts of the private- used to contend for a minimum of 1000 cubic feet of space per man in barracks. The best physiological authorities appear to agree upon about 800 cubic feet as the minimum which can be arranged for with safety to individuals in prisons, work-houses, schools, factories, and so forth. The estimates of this class, however, are principally made with rticrcnco to the nocturnal occupation of apartments. In many of the sleeping chambers in hotels in Canada and the United States, the capacity does not exceed from 1200 to 2000 cubic feet, without, in many instances, any provi- sion whatever for supply of additional fresh air or for the escape of the vitiated. Now such estimates are undoubtedly those which experience has shewn on the whole to suffice without entailing an intense perception of inconvenience or of injury to health. Yet the method altogether may be confidently pronounced to be fallacious. At a rate of vitiation of only 2 J cubic feet per minute, the amount, in a close apartment, occupied during about eight hours, would render the air of a space of the above dimensions unfit for respiration. But for a peculiarity mentioned in a preceding page, the occupants would find the resulting inconvenience unendurable. Admitting that through unavoidable crevices about the door and window the external air must produce some changes in that of the room, still these can only be very partial, and altogether insuffi- 91 lied for res- IreftJy been nil our paa- y, and even ucstion kas f air which ruspiration to allow 80 .utlioritative 800 to 1200 upation will isures being » Sir C. Na- account of 10 private — of space per C3 appear to irhich can be work-houses, 188, however, ccupation of in hotels in exceed from !8, any provi- )r the escape h experience igan intense th. Yet the be fallacious, minute, the eight hours, ions unfit for iceding page^ unendurable. ,he door and in that of the •ether insuffi- cient to himlcr the diffusiop of carbonic acid, in excels, from be- ing complete throughout the limited space. Diirinjj a cool night, that poisonous substance niimt pour down ngain nbout tlit> aleeper, n jgai i ia r''' -■-xsmu uiff^^l'.-^ ■ g-— a tij i.'i^:i^^^&3Mi^-3i\; 38 increase that proves grateful to particular consiitutions. 40, 50, and even a larger number of cubic feet per minute had been given with advantage in some cases." It might be expected perhaps that the estimates should be di- minished with respect to the quantities of air for respiration, which ought to be supplied in our school-houses, in connexion with the foregoing considerations. To what extent ought the statements made to be modified in the case of children and youth of both sexes, who are attending schools, and therefore for the most part confined to one apartment during the greater portion of every day ? So far as a judgment can be based on the exhalation of car- bonic acid alone, it would not appear that a school-room requires 80 large a supply of air, in proportion, as would be needed if the apartment were tenanted by adults. A boy for instance frora^ the age of 8 to 14 or 15 does not consume more than from ^ to | the absolute quantity of oxygen absorbed by an adult. But if we consider the nature of their occupations while in school under their teachers, the comparative delicacy of the organization of the young— the need of every aid towards cheerfulness and good tem- per—their violent activity when out at play, often resuming their seats with their bodies covered by perspiration and their clothes saturated with moisture ; then I think we shall see that we ought to be as liberal to them as towards adults. We have also to take account of their greater susceptibility to disorders, incidental to youth, and the greater facility with which infections maladies may be communicated, unless provision exist for an abundant ventilation. It would appear that in Upper Canada this sabject has engaged sufficient attention to induce the issuing recently of plans for school-houses, and for heating as well as ventilating ar- rangements, under the auspices of the department of public instruc- tion. It is there suggested that a rate of not less than 1 78 cubic feet of space to each pupil should be reckoned necessary in the dimen- sions of every school-room, and that the heating and ventilatmg arrangements should be governed by an allowance of 200 cubic feet per hour for each pupil. I shall allude to this again further on. In Lower Canada, owing to various causes, amongst which may 89 tutions. 40, ute had been sTiould be di- ir respiration, in connexion Bnt ouglit the rcn and youth refore for the ater portion of ilation of car- room requires needed if the tance from the ■rom 4 to I the It. But if we 1 school under mization of the and good tein- resuming their i their clothes 3 that we ought jve also to take 5, incidental to itious maladies ir an abundant da this subject ling recently of ventilating ar- f public instruc- nlTS cubic feet y in the dimen- and ventilating ce of 200 cubic ingst which may be included the still very recent establishment of an eflBcient edu- cational department, the state of the schools, in this vital particu- lar, is less encouraging. In country parts, especially, ventilation is wholly neglected, and pupils, at certain seasons of the year, are congregated in the single-room school-houses in numbers far too great for their dimensions.* Owing to the way in whicL the ex- penses of erecting these are provided for, cheapness alone seems to be consulted. The result is at present a most discouraging in- stance of unwholesome heating and deficient ventilation i:i the elementary schools and academies. It appears requisite to make a few more practical observations on this part of our subject, upon the conditions of purity and temperature already slightly noticed, the former a point of such vital consequence to our comfort and our health, and the latter forced upon our attentior. u^ LLo/.g'"-"'" character of our climate. With respect to purity it must be f.^in that the ventilating process must begin with furnishing fresh, wholesome air. Ac- cordingly in the midst of a crowded population it would appear to be often no e^sy thing to secure that essential, 07.'ing to the state of the streets, and the immense extent of underlying cellar- age, the prevalence of epidemic diseases and many other causes which present themselves in the experience of dwellers in cities. Under such circumstances, it would appear, that the only safe procedure is, to derive the air entering from as great an elevation as possible — as through ducts, or channels, constructed to lead down- wards, outside the houses into the spaces through which it is de- livered into the lower parts. The reason which recommends this plan as worthy of adoption is perhaps obvious. The rising causes of vitiation in the external air, are very quickly modified by dif- fusion, and so far dissipated in the atmosphere, that there is usually, a great diflference, as regards purity, between air procured at the'level of the streets and cellars, and that derived from sources 30 or 40 feet high. Nor does this plan interfere with the addi- tional precautions that maybe thought requisite at times when • it should be mentioned here that the same apartmenta are often occupied for hours together by assemblies of people, many of whom are adults, as in the cases of religious meetings, singing classes, municipal and other electoral proceedings. »inl mi 40 the contiguous atmosphere is found to be unusually contaminated or too damp, — such as causing the air of ingress to pass through in contact with purifying materials, as water impregnated with lime, preparations of lime and chemicals, such as muriate of zinc, and possibly sulphate of zinc, which is so extensively produced now in electrical processes, without, I believe, any known corres- ponding outlet for its application in the arts. The entrance of soot, dust, &c., may be prevented by making the air in its ingress pass through gauze. Amongst other means of local purification, I may here mention vegetation. Its presence has been known to pro'e a valuable safeguard in the worst situations. Its removal, whether on pur- pose or accidentally, has, in numerous instances, been found to entail loss of health upon neighbouring residents ; for where the vegetable flourishes, and becomes rank, man by inhaling the prin- cipal elements of its support would lose his vigor, I need not dwell however on this point further, and shall only add, that per- sons, especiaiiy in what are termed unhealthy situHtions, may de- rive from this source, a truly serviceable adjunct to their other re- sources for protecting themselves from the impurity of the outer air, by cultivating appropriate vegetable productions, whether trees, shrubs, or even common garden produce and grasses, as much as possible in the immediate vicinity of their habitations. The temperature of the air supplied in a ventilating ^"ocess should be so regulated as to limit the range from about 65'* to "70" Fall, — this amount being, upon the whole, thnt which is ordinarily most grateful to human feelings, and suitable to the wants of the system in a state of health and vigour. In this country it is quite common, owing to prevailing modes of heating, to find ourselves breathing vei'y dry air, which has either been partially disorganized, through previous contact with heated me- tallic surfaces, or which, through a like cause, has been rendered the vehicle of particles of animal and vegetable substance, scorched and partly decomposed. It is well known that several kinds of heating apparatus, while promoting the ingress of warm air, and thus satisfying one essential condition of ventilation, are yet liable to the serious objection just stated. At the same time it is grati- fying to find that attention is manifestly directed by a few towards ■f mu. 41 contaminated pass through regnaled with luriate of zinc, vely produced known corres- e entrance of • in its ingress here mention '6 a valuable ether on pur- )een found to for where the iliiig the prin- ". I need not add, that por- tions, may de- their other re- fcy of the outer ions, whether id grasses, as habitations, ilating r'ocess about 650 to that which is luitable to the gour. In this ides of heating, as either been th heated me- been rendered stance, scorched iveral kinds of warm air, and 1, are yet liable time it is grati- r a few towards the subject of ventilation itself, in the introduction by patentees and inventors, of new kinds of apparatus, in the recommendations of which to the public we may observe the claim occasionally set up of having provided for that object. I do not mean to insimiato that confidence can or ought to be entertained in the efficacy of plans advocated by persons inter- ested in particular heating appliances. Persons are often seen to be biassed in favour of their own inventions, and in treating such a subject as this are liable to omit, unintentionally, the con- sider'ition of other essential elementB not precisely connected with the mechanism or efficiency of an apparatus for furnishing caloric. We are bound to consider our own health in preference to the merits of any invention whatever, whioh has the production of heat merely or chiefly for its object. Every person indeed must in this behalf use his own judgment, ba&jd upon a recognition of the established laws of science, whose disinterested purpose is truth and the welfare of mankind. I shall conclude these remarks by stating, that, while it is easy, in our rooms and houses, to judge of changes of temperature, by th) employment of the common thermometer, we have less con- venient access to instrumental means of estimating the purity of the air. Lime-water is a well-known tect of the presence of carbonic acid gas, which it shews by becoming turbid on exposure to air in which that gaa is contained. Dr. Reid recommends the use of what ho calls a carbonometer. It may consist merely of a stoppled phial, containing water, with a bent glass tube attached, for holding a little lime-water in its angle, and so ar- ranged, that the evaporation of the water, consequent on a re- moval of the stopple, may cause a portion of the air of an apart- meni, to pass through the bent tube.* 2. SiMj)le Contrivances for Ventilation.— Wq now enter upon the examination of a few arrangements and processes intended to fulfil the conditions and secure the objects of ventilation. • aince tais was written, a notice has appeared in a recent number of the London Builder of a new instrument, styled a Sfpometer, porUble and otherwise convenient for use, by the indioationfl of which, it is said, the varying degiees of purity of the air, in different situations, arc clearly shown, and in instances Mhere varlationn of quality are utterly unappreciable by the human senses. mi Ml 42 Now to suppose that this has been perfectly accomplished by any system yet devised, in a manner that meets all requirements, under all circumstances, would imply a degree of perfection in art, which, to say the least of it, has not been attained. Even in the open air, although the products of lespiration and cutaneous exhalations, leaving ns at the heat of the body, are instantly and wholly carried off, yet in several other respects (as for instance temperature and humidity) the conditions to perfect ventilation are seldom all present ; much less then can it be expected that any single set or system of human devices can secure a perfect adaptation to all the wants created by our artificial modes of liv- ing within doors, modified, as these are, by defective architec- ture. I shall proceed to take up, in the order of simplicity, some of the methods which have been adopted, or proposed, for ventila- ting buildings. I omit, as immaterial to our present purpose, those plans that are carried out with the aid of powerful appara- tus and machinery, such as fans, wheels, blowing-machines, and so forth, employed in public edificee, and in cases where expense is unimportant,— only referring, perhaps, occasionally, to some of their minor details for illustration's sake. I also exclude such as are inapplicable in our extreme climate, although they may be remarkable for ingenuity and usefulness elsewhere. Class 1. The simplest and most common of all methods of ven- tilation consists in the use of the ordinary doors and windowR, which, when constantly attended to, by persons conversantwith the proper- ties and motions of gaseous bodies, and alive to the necessities of the case, may, to a certain extent, often serve the purpose of main- taining a tolerably salubrious atmosphere within. But I only name this here on account of the objections which are justly raised against what is, perhajjs, merdy superior to no ventilating pro- cess at all .Whatever the accuracy of fitting may be, quite a large quantity of the external air, as we have ama, will force itself in, wderjaeath and beside doors and windows, unless the demand which may exist be met by some other special provision; also above the doors, amd along the sides and tops of window-frames, air will escape, — the more rapidly when the external temperature is less than that within. e.:i». irapHshed by requirements, perfection in ed. Even in ad cutaneous instantly and s fur instance ict venlilatiou expected that sure a perfect modes of liv- tive architec- icity, some of 1, for ventila- sent purpose, verful appara- machines, and vhere expense ly, to some of ;clude such as they may be ethods of ven- indowp, which, itii the proper- I necessities of •pose of main- But I only e justly raised entilating pro- i, quite a large force itself in, i the demand trovision; also rindow -frames, ftl temperature When several persons occupy an apartment of moderate di- mensions, it is needless to sRy this escape is wholly insufficient, and the vitiated products speedily disperse throughout, and, by their greater elasticity, impede the draft and incoming air in such a way as to cause an almost stagnant state around. The openmg of doors, aad especially the upper sashes of windows, then becomes often ncce8sary,but is liable to objection either in summer or winter. In winter, because the outer air rushes in and forces the air— the most vitiated— at the ceiling downwards, bodily, cooling it and throwinL, 't around us so that we cannot fail to breathe again that which has already passed out from the lungs. Even in summer there are frequent occasions when dust, noise, and rain render the use of the window in this way undesirable. Faraday, on this subject, remarks, " The buildei makes the doors and windows to fit as tightly as possible, and then the poor chemist is called in to provide fresh »ir." Dr. Birkbeck, in giving evidence before a committee of the House of Commons, stated, " Heating ftnd ventilation seldom enter the mind of the builder when he projects his building : he trusts to the doors and to the windows, to neither of which belong the business of ventilation. The doors admit the occupants to the chambers, the windows the light ; and apertures ought to be introduced for ventilation, as regularly as the other openings." In fact it will be admitted, that the process should be independent of doorS or windows, if the purpose be to supply air in the condition required, equably and conveniently. Those persons, who, on all occasions, when the weather is not too sevel-e, throw open every aperture, in order to realise in a house the advantage of a more perfect process which tak«;s place jwft*- rally in the open air, gain their object very imperfectly owing to architectural arrangements, while the currents of air thus set in motion are themselves fi-equent causes of injury to health. It would be tedious to enlarge upon these points, and I shall only add the remark, that such methods o^,casion too much per- sonal trouble, and would require a constant attention to the duty of changing the air within such as is never afforded. 2. There are several simple devices in conjunction with the use of doors and windows for providing the necessary supply and es- cape, avoiding also the introduction of other apertures, excepting .4 44 such as are requisite for egress of vitiated air, into chimneys or communicating flues. A crevio is cut along the upper part of the window-frame, quite through to the outside, and underneath it is placed a thin shelf of wood or tin, sloping upwards. "Unless \ in extremely cold weather, this is found t(> work as well as any X other of the simple plans of admitting fresh air. The outer air is thus directed upwards towards the top of tho apartment, where it mingles with the more heated, and descends with tho latter in part to feed the fire or stove. The opening into the flue serves to C/arry off into the existing draft, with the smoke, at least a con- siderable portion of the vitiated products of respiration and com- bustion. Another method is to provide a recess in the wall of the room, immediately below tho ceiling, and above the window, the whole width of the window, and about a foot deep, and to have a perfo- rated plate of zinc of the same size fitted in ; and behind the recess, an aperture leading outwards, through the wall, the size of aper- ture being about 9 inches square. In this case, the air entering or escaping, must pass through the perforations, which causes a certain amount of dispersion of the external air at its ingress. Eometimes a pane is removed from the upper part of the win- dow-sash and a tin or wooden door hinged underneath, w as to admit of being let downwards and inwards, more or less, accord- ing to circumstances. 3. Another method is the old-fashioned contrivance of placing, in one of the glass spaces, a frame containing a circular tin plate, having attached to it a wheel, mounted on an axis, with radii or vanes, bent obliquely, which, when acted on, forces the air round like tho vanes of a windmill, and, dispersing it somewhat, pre- vents a distinct draft from being felt. 4. Another plan, sometimes seen in small houses, is to replace' a pane of glass by a frame, in which a number of strips of plate- glass are arranged in the manner of a Venetian blind, and having an adjusting motion, so as to regulate the supply of air. 6 and 6. Besides these there have been used perforated panes of glass, and elongated holes in the wood-work of window-sashe?, having sliding doors attached ; as well as a nuraber of other little contrivances, equally simple. .lA; »i*> 4i chimneys or upper part of d underneath ards. Unless J well as any le outer air is lent, where it the latter in flue serves to least a con- ion and com- L of the room, )w, the whole have a perfo- ind the recess, size of aper- air entering inch causes a 3 ingress, rt of the win- eath, vo as to : less, accord- ce of placing, ular tin plate, with radii or the air round mewhat, pre- is to replac a trips of plate- d, and having air. •forated panes rindow-sashe?, of other little Of all such as the above, it may be said, I think, that though inef- fectual, and even insignificant, when compared with other arrange- ments to come under our notice, the adoption of them in thousands of the smaller habitations in this country, where no ventilation is ever thought of, would be a considerable step in advance, and confer a g"reat benefit upon the community on the score of health. It would be a mistake to assume their inutility because they are not the means of frequently changing the entire air of an apart- ment. The principle of diffusion of gases alone would render those simple means decidedly advantageous in all states of the atmosphere, by preventing within an apartment any excessive ac- cumulation of an injurious kind ; but, by having them constantly in operation, whether in the windows of small parlours or ot the bedroom, or sick chamber, they would, in many instances, suffice for all ordinary occasions, and prove the welcome means of pre- venting the spread of infectious disease from centres in a way within every person's reach. In addition to means of the above- mentioned class, which may be regarded as chiefly, though not wholly, useful for admitting air from without, we must note the opportunities of escape aflPorded by small openin.os made into chimneys, or overhead through the ceiling or roof* It must be admi'ted that such modes of escape afford facilities causing a greater expenditure of heat than is desirable, in our climate, dur- ing winter. The ascending heated air is commonly supposed to make for those openings in a body, so that some parts of a room, which are in its course from the source of warmth, are unduly warmed, and other parts kept at too low a temperature. I am of opinion, however, that this defect is somewhat overrated, and that it may be partially remedied by regulating the sizes of the upper openings, and by other means (not necessary to describe here) by which the heated air itself is made to disperse as it rises. When a heated gas ascends or moves otherwise through another, • For egress, in connection with the use of the ordinary stove-pipe, it has been proposed to adjust an inverted funnel to one of the lengths of the ri>.9, 90 that the vitiated air of an apartment, entering into the flue through the mouth of the funnel, may be constantly carried off in the draft together with the heated products of combustion from the stove. X iidaia«iit»a.a i i.--,^t..^gMa«tift'» '' --■jJtfeMa ! ftaffl.!r ! ! 48 • at a lower temperature, it does not, unless the pressure or draft ia great, move in a compact mass like a solid or liquid body pro- \ jected in space. The motion is a rolling one : the unequally heat- ed gases pushing out into each other in a manner wliich it is not easy to describe, but which can be witnessed in the convolutions of bodies of smoke in air, and in the movements of masses of stenra issuing from a locomotive engine in cold weather. The same sort of movement takes place in an apartment, occasioning s greater amount of transfer of heat, laterally, than is generally supposed, before the heated air is finally evacuated at outlets in the ceiling. But if the expenditure of caloric were greater still than it actually is, it is surely preferable to have such outlets, which can easily be regulated in size, by means of slides adjusted to them, rftther than in all circumstances to force the warm air to come down again, bringing with it the products that must, at any coat, I o quickly got rid of, in view of health. We have, thoretbfe, in these simple arrangements, one or oth«^r of the methods of letting in and dispersing the fresh air through an upper window-pane, and the addition of a hole regulated by a slide, and communicating with the chimney, or through the ceil- ing overhead ; a system of ventilation within every householder's reach, and one which, if it were adopted, would be a great im- provement in the ways of living that actually prevail. I must here allude to the sort of ventilation which is met with in a great many private houses, and hotels, of the simple kind now under notioe. A swinging-sash, moving, either vertically or horizontally, is fitted above the doors— more particularly in thi sleeping apartments. By these the circulation of air is promoted in the chambers, and along the passages and corridors. But, unless a further provision be made, so as to allow of escape into an upper story, and out through the roof, it ia impossible to con- sider the system a judicious one. In hotels, especially, such apartmente too often become receptacles for large volumes of un- wholesome vapours ascending from the public rooms and cooking- places below ; and in the night, when all windows above are closed, the best that can be said of it is, that every occupant gets his fair share of the unctuous vapours and products of respiration and combustion, and of everything else that permeates the atmosphere ':rSBbi£S^» ssnre or draft aid body pro- lequally heat- hiuh it is not ) convolutions of masses of 'eatbcr. Th« t, occasioning n is generally 1 at outlet in } greater still J such outlets, lidcs adjusted the warm air , that must, at }, one or otb^r h air through egulated by a ough the ceil- householder's be a great im- il. sb is met with le simple kind r vertically or iculaily in tb^ ,ir is promoted irridors. But, of escape into ossible to con- pecially, such rolumes of un- s and cooking- love are closed, lupant gets his *espiration and he atmosphere 41 of the building. In such a situation, the transient occupant of a sleeping-room is often completely at the mercy of a hurtful sys- tem ; 80 that it becomes a question, whether it is not, on the whole, better to close the ventilator, and then, after admitting for a time the purifying external atmosphere, trust himself to the hazards of a night passed in a close room containing from 1500 to 2000 cubic feet of air pure at the outset. I may quote, in passing, the remark of Dr. Reid on the subject of deficient venti- lation in hotels : "Travellers, and indeed all persons, should be charged only half-fare when they partake of refreshments in an ni-veutilated apartment; for many are the unrefresbing meals and subdued appetites that destroy the strength of the constitu- tion in apartments loaded with the vapour of respiration and ex- halation." If, however, measures be taken for maintaining in a suitable condition the air of halls and passages, the method of ventilation by means of a swinging-sash over the doors of apart- ments is undoubtedly one of the most convenient that can be em- ployed. It might appear to some that the effluent air from each room would vitiate that which enters, and thus defeat the purpose ; but a remarkable peculiarity of gases, when in motion through the same channel in opposite directions, presents itself in correc- tion of the supposed injurious effect. The currents divide, each occupying a side of the conductmg channel, with far less inter- mixture than might be expected ; and, when a thin solid partition or diaphragm is placed, the separation appears to be rendered cona- plete. This is illustrated in .\ familiar manner by the way in which the producte of combustion are carried off from within a receiver through a tube, while, at the same time, the air necessary to support it is passed inwards ; a diaphragm, in the axis of the tube, dividing the ingoing from the outgoing current, in a way that keeps the flame alive, and which, when the diaphragm is re- moved, is extinguished. In some such way alone can both cur- rents of influx and efflux be sustained in many cases that might be cited ; and of which a good example is furnished in the venti- lation of a beehive, by the labour of their interesting occupants, whose dwelling has only one small hole underneath for maintain- iag communication with the external air. As regards the whole class of processes of ventilation adverted iMMji l Sa. 48 to, in which simple expedients in connection with windows and dooi-9 are employed, it mgiit be questioned whether they are not, after ail, those which mosi merit the attention of the bene- volent and ingenious, with the view of perfecting them as much as possible, and of encouraging their introduction in the habita- tions of that large number of persons who will not, or cannot, endure the cost of more elaborate arrangements. Under some such impulse it was, that, nine or ten years since, at a period when the Choiera was rtiging in London and other cities of Great Britain, Dr. Arnott succeeded in inducing the Board of Health to announce, officially, in the London Gazette, that, " in every ill-ventilated dwelling, considerable and immediate relief may be given by a plan, suggested by Dr. Arnott, of taking a brick out of the wall, so as to open a communication with the chimney, near the ceiling of the room. Any occasional down- draft will be more than compensated for by the beneficial re- sults of this simple ventilating process." The Doctor, who appears at all times to have had the welfare of his suflFering countrymen at heart, — freely communicating his experience, and his inventions also, without aiming at securing pecuniary advan- tage to himself,— devised a useful little self-acting contrivance, to be fitted into the chimney-hole, which he described in a pub- lished letter, dated September 22, 1849. Had a more complete and costly process been insisted on, it is almost certain the results would have been insignificant; whereas, to use the Dr.'s own words, in the letter referred to, " The advan- tages of these openings and valves were soon manifest, and they arc now in very extensive use. A good illustration was afforded in St. James's Parish, densely inhabited in some quarters by the families of Irish laijourers, who sent an enormous number of sick to the neighbouring dispensary. I was consulted respect- ing the ventilation of such places. The decided effect pro- duced at once on the feelings of tho inmates, was so remarkable that there was an extensive demand for the new appliance ; and, in consequence, it was soon reported in evidence before the Commission for the Health of Towns, and in other published documents, that there was an extraordinary reduction, both in the number of sick applying for relief, and in the severity of dis" 49 nndows and er tliey aro of the bene- lem as much tho habita- •t, or cannot, Under some at a period her cities of ;hc Board of He, that, " in lediate relief of taking a ;ion with the sional down- beneficial re- Doctor, who his BufiFering perience, and miary advan- )ntrivance, to ed in a pub- tisted on, it is jnt; whereas, "The advan- 'cst, and they was afforded arters by the IS number of ulted respect- i effect pro- remarkable tpliance; and, e before the ier published stion, both in everity of dis* / eases occurring. Wide experience elsewhere Iiim since obtained similar results; so that most of tho hoRpitals and |K)or-house8 in tlic> kingdom have now these chimney-valves ; and most of the medical men and others, who have published of late on Sani- tary matters, have strongly recommended them." It should bo noted that Dr. Arnott, although an inventor of many ingenious contrivances, not only preserved no secrecy re- specting their principles, but is commonly esteemed to have boon unbiassed by any mercenary feeling that might warp his own judgment and damage the influence of 1)19 Jidvocacy of vontila- ti(Mi. On the contrary, all ho says on the subject is entitled to have great weight ; because it was seen, that, with disinterested feelings of humanity, he united an enlarged experience and know- ledge of scientific principles. Before finally dismissing from our view the class of most simple ventilating arrangements, it may not be out of place to remark, that their extreme simplicity or common-place character ought not to be pennitted to stand in the way of recognizing their value, or of endeavours to extend the knowledge and use of them. Natural processes in general, conducive to our welfare and hap- piness, become, when comprehended, simple in our estimation. If art lags far behind nature, in the production of contrivances suitable to the attainment of ends sought, it is chiefly in this very feature of simplicity that the deficiency is most apparent. To reject or despise any contrivance, on account of its simple cha- racter in comparison with the magnitude of its purpose, or in the face of more elaborate devices whereby the same may be accom- plished, would seem to be only a poor imitation of the Syrian leper willing to accord compliance, had the prophet enjoined ^'■aome great thing," but scornfully contrasting the little i/brrfan with the Pharpar and Abana, " better than all the waters of I$rael" • Amongst the simple arrangements noticed in this chapter, I have not expressly named that proposed by Tredgold, and, more recently, extended and patented by Dr. Chowne — the principle upon which it is understood to act in those cases in which it has been shewn to operate sncceasfuUy, being to say the least of it, a somewhat doubtful assump- tion. A syphon, the legs of which are of unequal lengths, being placed D 80 rertically, with the bend downwards, ithaabeen M«ert«d that a current will be 8Ur»ed downxcardi through the Bhorter leg and upwards through the longer. Tredgold, however, appears to have had In riew the pre- sence of a fire, the mouth of the shorter leg being placed near to the ceiling, and the longer leg situated contiguous to and entering the chimney. Dr. Chowne proposed to carry one or more tubes, opening near the ceiling, and passing from the apartments of a house to the neatest chimney in such manner as to enter the latter at points not far above the fire places. Thus the chimney itself is made to form a part of the longer leg of the inverted syphon. In a great many cases in which the occupant of a house desires to provide for the escape of foul air from particular apartments, the plan might work successfully, even when no artificial fires are In use, because ths requisite draft might be produced by the stronger action of the sun upon the exposed chimney. It has been employed to carry off the heated producU of combusUon from lamps, gas-lights, 4c. at that a current wardi through Tiew the pre- d near to the i entering the lubes, opening bouse to the points not far form a part of cases in which pe of foul air iessfully, OTen Iraft might be osed chimney. of combustion CHAPTER V, ON BOMB OF TUB VARIOUS METHODS OF VENTILATING DWELUNO- UO'TSKB AND RCU00L8. The proper time for arranging a system of ventilation for a building, intended to be occupied as a dwclling-l.ouse, occurs when the plans for the structure are heiny laid down. It is then tlmt the important object can be provided for with the greatest cer- tainty, and with the least expenditure, both of money and inge- nuity. 1. One principal requisite is a shaft or vertical channel — in an extensive structure, two or more such shafts — situated conveni- ently with respect to the halls, passag.^s, and apartments, and passing upwards through the entire height of the building, from the basement, and extending to some littU levation above the ridge of the roof. In mo-t cases the ordinary chimney-flues may be made to answer the purpose ; but the intended uses will be more completely and more satisfactorily accomplished if the shafts be merely, contiguous to the chimney. In either case, the heat derivable from the ascending products oi" combustion may be turned to account in producing the requisite upward current in the ven- tilating shaft. In the next place, the interioi of the ventilating shaft 's to be dividefi a number of veitioal channels or compartments, by means ol partitions, and, wliile the process of construction is going on, communications provided for at suitable places, both between the shaft and the chimney, a 1 between the shaft and the several stories and rooms of the building. Each separate room and sleep- ing chamber should have, if possible, a distinct channel assigned to it in the ventilating shaft. The use of the shaft is to carry off the vitiated air, and the va- rious noxious gases that may be generated at any time in the house. By an easy arrapf^ement, two sik -^ shafts, having several vertical and distinct channels in each, can be provided for — one on each side of the main flue — in couuection with each chimney. Ill; 62 The best situations for openings from rooms to be made for the purpose of drawing off, as it were, the damaged air, would, at first sight, appear to be the highest altainable near the ceihng, the inlets being suitably shaped so 'as to present no ut necessary obstacle to the free movement of the gases ; bn- considerations relating to the economy of heat and ite more equal distribution serve to modify that conclusion. Hence, it has been recommend- ed to have two openings for escfipe,— one in the highest and the other near the lowest part of the room,— so thci,, in practice, when it is conceived that the effluent air is carrying off too much caloric; then, by means of suitable' valves or registers, the upper outlets ni'Ay b6 wholly or pariially closed, and the Io\ver ones made to assist in effecting the discharge. In some instances, the idea of economizing heat, prevailitig over all other considerations, has led to the use of oh^ opening only, situated near the floor. An airangement siich as that which has been thus familiarly described suffices effectually for escape of the products of respira- tion and combustion in a dwelling house, so long as the heated chimney serves to warm the adjacent shafts and their compart- ments Even in the summer time, when fires for warmth are not in use, it becomes available to some extent. But in any of the larger dwelling houses it is generally possible to create the requi- site draft at all times by having a fire-place, whose flue enters the main chimney, put in operation in some more remote apartment, where the heat might not occasion inconvenience. In towns where gas-light is used, antj in cases where the main flue, having no compartments, is 'empl9yed as a ventilating shaft, a pipe with one or two burners might be laid on and disposed securely within the chimney at a convenient point; the heat '"rem ihe burners could then, at any season, be made to maintain some draft, as in the foregoing instance. Jlven in smaller habitations advantage might generally be taken of the draft in the flue from the cook- ing apparatus — this being commonly in operation at all seasons of.the year. ^ Tq avoid a lengthened description of details relating to the positions- of the openings and the arrangement of the compart- ments of the ventilating shaft in connection with ihe several be made for air, would, at ir the ceiling, uunecessary jonsiderations il distribution 1 reccimmend- gliest and the ,, in practice, ; off too much ers, the upper »e lover ones instances, the sonsid'jrations, r the floor, bus familiarly lets of respira- as the heated tbeir compart- armth are not i in any of the 3ate the requi- flue enters the ote apartment, ce. In towns in flue, having ft, a pipe with ecuroly within ■m the burners me draft, as in ons advantage Tom the cook- at all seasons elating to the ■ the compart- th the several floors, I refer to diagrams* given at the end. It may be stated, however, in brief, that the outlets for vitiated air should be placed as much as possible opposite to and distant from the places of entrance for the fresh air ; so that the latter, being introduced warmed in the winter time, may be compelled to diffuse its caloric more widely before finally reaching the places of escape. With respect to the supply of fresh air needed, there are, asH« well known, several kinds of heating apparatus now in use, by means of which the vital fluid is warmed and passed into the apartments ot a building in any required quantity. Usually the same inlets as are employed in'wiiiter may be used at other sea- sons and without the employinent of any other means of ingress, provided only a draft in the flues is maintained for the evacuation of the air required to be withdrawn. Some imperfections, however, and occasional difficulties can- not but be expected to attend the carrying out of this or any other system of house-ventilation in our excessive climate. But the principal circumstance that stands in the way of our attain- ing our purpose perfectly, appears to grow out of the difficulty of reconciling two opposing conditions. The one is, the deficiency of entirely self-acting means of producing a draft, in lite summer time, to bring in fresh air and to carry off vitiated air through its intended outlets. The other consists in having too much draft, in connection with our powerful heating arrangements, to accord with economy and otherwise suit our purpose during our rigorous winters. The economical adjustment of these opposite conditions is a thing much to be desired in view of improvement in domes- tic architecture. In conjunction with those modes of heating in which pipes are employed conveying warm water or in carrying steam through- out a building, it is only necessary to enclose portions of the con- ducting pipe within the entilaving shaft or in channels commu- nicating with the outer m. In this way, as some contend, the most eflaciently acting process of evacuation is provided for the foul air. Passing through air-chambers constructed expressly for the purpose, the quantity of warm air required for breathing pur- i • See explanatory note at the close of this chapter. 64 poses is furnished in a manner similar to that which follows on the use of air-chambers with stoves. Hence by either method of heating, together with the ventilating-shaft, the conditions of warmth, ingress, and egress are adequately fulfilled. 2. But it is not so where only the common stove is made use of, without an air-chamber. The air to support combustion and for breathing, in that case,find8its own way in through crevices and other inlets, from all quarters, entering cold, and the greater por- tion making for the stove. Several considerable inconveniences are experienced in consequence, which it is unnecessary to detail, but which do not appear susceptible of removal, consistently with the conditions of that mode of heating. An adaptation, however, of the common stove to the purposes of bringing in the air for its own consumption and also that required for other uses, has re- cently been proposed,* and partially introduced. As the plan is further recommended by an accompanying arrangement for ven- tilation, it appears proper in this place to make such allusion to it as may aflford a general idea of its nature. The method is, sub- stantially, to attach to a stove of peculiar shape, or (as it may be styled, for the purpose of illustration) tlie furnace, in which the fuel is consumed, an outer case or covering, between which and the inner part the air is made to pass, and subsequently to flow outwards and upwards. All the air required, both for combus- tion in the stove and otherwise, is conducted, from without the building, in an air-tight channel, which is constructed eypressly for that purpose, and terminates, inside, in an opening through the floor, over which the stove is placed and closely adjusted- The air then passing between the two metallic walls of the stove, is heated and passed in. It is essential to the arrangement that the foundations of the house and the walls of the building should be perfectly tight, so as not to admit other air besides that which is transmitted in the way described. Thus the condition of in- gress of fresh air, warmed suflSciently, but not, as is asserted,f excess-ively heated, is complied with. ■• By Mr. Ruttan, of Cobourg, C. W. f A number of testimoniala, and some descriptions, from which the facts hero stated have been gathered, were published at different times by the patentee. ;h follows on ler method of couditions of I 19 made use mbustion and h crevices and e greater por- nconveniences sary to detail, isistently with tion, iiowever, the air for its ir USPS, has re- A.8 the plan is ment for ven- ch allusion to lethod is, sub- (as it may be in which the 3en which and [uently to flow [i for combus- m without the cted eyprossly jning through osely adjusted- Is of the stove, angement that luilding should des that which jndition of in- 8 is asserted,! from which the t different times 86 The accessary arrangement, whereby the warmth is retained and diffused through the building, and the process of evacuation effected, appears to be such as would satisfy all who do not object to the situation of the outlets, which, in the different apartments, are placed low down near the floors. Each outlet communicates with channels leading down to the lowest floor. 'J'he escaping air is made, in consequence of a peculiar method of construc- ting this floor, to pass along underneath, until it reaches a cham- ber or duct whence it moves into a shaft or chimney, and is eventually carried up into the atmosphere without. As respects the applicability of this method of warming and ventilating to dwelling-houses, and indeed to buildings of aiiy kind, it may be stated that it must be specially provided for in the outset when the structure is being built,— or at least the buildings must be expressly contrived or altered for its reception. The amount of heat radiated from the or.ter walls of the stove is stated to be, under judicious management, quite moderate. Any improvements such as are claimed in behalf of this mode of heating, cannot ftiil to prove highly acceptable, especially as respects the avoidance of cold currents about the floors of rooms, and the introduction of warmed fresh air, in conjunction with the use of stoves in apartments. The foregoing system appears to be essentially a winter arrangement as regards ventilation. 3. There are numerous other adaptations of mere stoves in favor of which their inventors claim efficiency both in heating and ventilating.* In a climate so cold as that of Canada in winter it is neither possible nor perhaps desirable to provide for the eSlcient working of ventilating processes independently of those for heating. Hence the desire of most inventors and patentees to secure for a power- ful heating apparatus, the additional recommendation of being adapted to promote the ingress of fresh air into a house, to warm it sufliciently, and to admit of easy instrumentality in pro- • A reference may here be made to the apparatus of Mr. Wilson of Upper Canada, the nature of which, together with diagrams showing the operation of a ventilating process in connection with it, and in a house warmed by his method, were published in a small pamphlet by himself. Mr. White of Montreal has brought out a very good stove, to which a complete system of ingress and egress should be applied. ,j|t KayjBaMap».i!#iift»-gWfMi"'?wsg.#'jMBJiiaiSi? ■»" 66 moting the discharge of vitiated air. There are, however, so many ingenious inventions, and, besides, so much of conflicting opinion about their comparative merits, that it would be iof. The other nection with a n underneath ses of an ele- sneral observa- been speaking. itary improve- ;y is not mere- te the existing ;h at ventilation imit the obser- ills of Legisla- , barracks, pri- lation ; and, to it at the public )e permitted to still more im- ansing process, nes — our fami- n constantly, — ir light than as here referred to nto our country I. I may be per- ritative influence Thich are wholly of those whose A.ccording to an er Canada there irince in 1856, of VL M more important than in the case of those other public structures, which, necessary as it may be to ventilate them, are in compari- son only occruiluiially uaed by the same persons. And when we consider that the life, and health, and prospects of an innocent child ought at least to ' as much cared for as the health of a prisoner, or the bodily welfare of a soldier or sailor, surely our school-houses ought to bo ventilated as well as our public prisons and barracks. The argument presents itself with still more force when we regard also tho more tender and delicn+f> organization of the young. If, by attending properly to ventiUtion in our homes and schools, we did not in the end prolong the span of human exist- ence ; still it cannot be doubted but that the various evil accom- paniments of this transitory scene would be largely diminished while life did last But the fact is, one can scarcely come to any other conclusion than that one eflfect would be the extension of the average endurance of life. Other undenisblo causes enter into considerations about lon- gevitj besides such as have been here referred to. We know, for example, that intense and long-continued activity of body and mi no, hardships, want of proper food and shelter, and, above all, excesses and moral depravity,— all more or less efficiently aid in shortening life. Yet, some of these very causes not unfre- quently, as has been alluded to, result from extreme neglect of cleanliness and ventilation, in their effects upon the disposition and habits of thousands. Finally, whether we concur with those naturalists who have endeavoured to make out the proper duration of an animal's life to bo five or six times its period of growth, which would assign toman 100 or 120 years; whether we adopt with some most learned and pious commentators— Muis, Cocceius, Hammond — that sense of the words in the 90th Psalm, which represents Moses as speaking of those particular Jews who were then with him in the desert, and not of the race of man generally, or whe- ther we take the literal meaning of his words and hold that man's ordinary limit is 70 to 80 years,— still it may fairly be questioned whether any single set of physical causes tend so much to shorten life, and to embitter it while it endure ., as bad ventilation. 00 • EXPLANATORY NOTE. In the diagrams for illustration, figufdS 1', 2, 3, 4, and 5 ttre intended to show the escape of vitiated sir into and through the ventilating-Bhaft, as well as the relative positions of the Joors, ceilings, and apertures for egress, in the case of a dwelling-house of three stories. In fig. 1, each aperture is at the ceiling, and there is but one channel in the shaft. In fig. 2, each aperture is at the 'ceiling, but the vitiated air from every story is prevfcilled ftom mingling with- that of the other floors, being made to pass out by it«elf from the ventilating-shaft, either through the wall into the outer air, or through the appropriate channel, leading into the nearest ^lyiptney. In fig. 3, the situr- 'ion of the aperture for egress is the same, but the ventilating-shaft is divided into vertical compartments, one of which is assigned to each floor. In fig. 4, the arrangement is the same as in fig. 3, with the addition of a second aperture at the floor of each story. Fig. 5 exhibits the same arrangement as fig. 4, the dark spots indicat- ing the positions of the openings for escape from the several stories of the building. In this case, the middle compartment of the ventilating- shaft is appropriated to the lowest story. Fig. 6 illustrates a plan of ventilaiing a dwelling-house of two sto- ries. A vertical section being made through the building and venti- lating-shaft, the latter is seen enclosing the flue from the heating apparatus;, situated underneath the lower story. The dark spots, with vertical arrows over them, shew the ingress of wariped fresh air. The other arrows indicate the circulation through the several rooms, and the subsequent mode of escape into the ventilating-shaft. In this case, the apertures for egress of vitiated products of respiration, &c. are situ- ated near the floor of each story. Fig. 1 is the vertical section of a building of several stories contain- ing two class or school rooms of the whole width of the structure. The letters mark the furnace ; the pipes for conveying fresh air, warmed, into the building ; the furnace-flue ; an,d ihe outlet from the ventilating- shaft. The packing of the foul-air flues, as well as the situations of openings for escape into the shaft, are also shown, in the side figure, fig. 8. Figs. 9 and 11 are sufBciently described in the statements attached to them. Figs. 11 and 12 need no further description than has been furnished in the text. As before observed, the opening for the ingress of the outer air is not given in these diagrams. 61 3. 5, Are intended ttlating-shaft, apertures for t one channel ited air from ! other floors, •shaft, either riate cIiannQl, same, but the ne of which is t h the addition spots indicat- eral stories of le ventilating- e of two sto- ,ng and venti- 1 the heating ,rk spots, with resh air. The al rooms, and In this case, 1, &c. are situ- tories contain- tructure. The 1 air, warmed, he ventilatingr le situations of the side figure, lents attached been famished >uter air is not mfmrnmrntmrnrmmmmmmm' es 1^ V ^ / at^ I • ! k ^ k k 1 II in