488 The Architectural Review and American Builders' Journal. [Feb., of all scientific men, there is another source of disease — concerning which there is unaccountable popular ignor- ance and apathy — equally deserving our attention. We allude to the use of gas, without sufficient ventilation. This has just the same effect, in rendering the atmosphere of apartments impure and poisonous, as overcrowding. The evil of overcrowding arises, as we are all aware, from the fact, that where a large number of individuals are crowded together, in a small space, they consume the oxygen of the air, and poi- son it with carbonic acid gas. Now, it has been proved by the celebrated Dr. Lankester, Sanitary Commissioner, in his Sanitary Report (St. James', West- minster, London, 1864-5,) that one gas- light consumes as much oxygen, and gives out as much carbonic acid, as Jive human beings. We have only to bear this in mind ; and when we reflect upon the reckless and extravagant manner in which gas is burnt in our stores, factories, work- shops, churches, theatres, sitting-rooms and bed-rooms, already too often over- crowded, we cannot be surprised at the inevitable —results, which necessarily result from such a process of slow poi- soning. We cannot be wrong in assum- ing, that a large amount of the mortality in our population, is attributable to the evils resulting from exposure to this influence, evils which are not, perhaps, felt at once ; but which too surely and insidiously undermine the constitution. To avert such evils, and yet employ gas, a very useful invention has just been introduced in London. The ar- rangement of the fittings is novel and effective. , Its purpose is to make the hitherto pernicious combustion a means of ventilation, not alone purifying the atmosphere, but securing a supply of fresh air. The invention, we allude to, is of the nature of a globe-lamp, pro- vided with tubes and brackets of such dimensions, as to carry off, through them, the vitiated air from the burner, and convey it, by means of metal pipes, to the chimney, or into a shaft specially prepared for the purpose. This inner pipe is surrounded by an outer pipe, which carries off the heated air of the room ; for by means of the heat of the inner pipe, a constant upward current is created, and a continuous system of ventilation produced, without any fear of draught or smoke. Provision is also made for the supply of external fresh air, so that the whole arrangement is as perfect and complete as possible. Houses in course of erection may have the ven- tilation pipes, &c, so arranged, during the process of the work, that the gas may be used in every part of the entire