OUR CITY CLEANSING.

New Zealand Herald, Volume XXXVII, Issue 11368, 10 May 1900, Page 3

OUR CITY CLEANSING.

TO THE EDITOR. Sir, —Now that our city is being inspected by Sanitary Commissioners, health officers, and the police force, to compel the cleaning of dirty yards, pulling down insanitary buildings, and having a general clean-up, I think the time opportuno to write a few lines on the subject of house and room ventilation, which I hope will bo of some benefit at this juncture, for, while cleansing the outsido of premises is a very necessary proceeding, it will ho very little use if the inside of our houses is allowed to be contaminated, and the residents to live and breathe in an impure atmosphere. t No dwellinghouse, shop, warehouse, or factory should bo considered complete without an offectivo system of ventilation. We have been taught that a healthy atmosphere is composed of nitrogen, oxygen, and carbonio acid, with a small proportion of watery vapour, which varies with temperature _ In the process of respiration and transpiration, we inhale oxygen slightly diluted with nitrogen, and wo exhalo carbonic acid in such a proportion (which, if not reduced by being diluted with tho other gases of tho atmosphere), but again inhaled, tends to produce results which are tho very opposite of healthy. It is assumed by reliable authorities that 20 eubio foot of air passes through a man's lungs every hour, and it is also proved that a healthy atmosphere ought not to contain more than one part in 500 of carbonic acid gas, and to koep up this proportion of puro air most of tho great authorities are agreed that it is necessary to have not less than 3000 cubic feet per head per hour of fresh air delivered into the rooms.

Now, in many of our dwellinghouses very little provision is made for a system of ventilation which will ho conducive to health, as we find in many cases tho rooms are not even provided with a ceiling contre, or chimney flue; in fact, no outlet whatever for impure air, and as the windows and doors aro shut (especially during sleeping hours), there is no inlet for fresh air. The expired air exhaled by a person breathing, and all vitiated air thrown off tho body, ascends to the top of the room, thus indicating its intention to make its exit in that direction; but on finding no outlet there, it will descend again, and is then retaken into tho lungs of the occupants, very often slowly, but surely, causing disastrous results. Now, in some parts of our city there aro comparatively small rooms (with no attempt at ventilation in them), occupied by two, three, four, and sometimes moro occupants during sleeping hours, and when wo think of each person inhaling and exhaling at the rato of 20 cubic feet per hour, and having to breatho the same air ovor and over again, you can well imagine that it does not take long to make the air of that room simply poisonous, and constitutions, which might have- been robust, aro undermined, and likely to break down under tho least strain. Of course wo must not forget that in wooden houses (especially) there aro air inlets and outlets between window sashes and shrinkage of timber, but not enough to mitigate the evil effects. What wo want in this matter is expressed by a great student of ventilation, as follows: —"To obtain everywhere tho temperature most congenial to tho human constitution and air as pure as blows upon tho hilltop." And to obtain this in our dwellings we ought to have a proper system of ventilation, which consists of two operations, viz., tho removal of foul or expired air, and tho introduction of fresh, pure air, and neither operation is complete without the other. I know thero are other agents, such as "cleanliness of the individual," "drain ventilation," etc., which must bo used to ensure a healthy community, but I must leave them for a futuro claim upon your valuable space.— am, etc., . , , ROBT. TODEHOFE. Auckland, May 8, 1900.