The air of towns / by J.B. Cohen.

  • Cohen, Julius B. (Julius Berend), 1859-1935.
Date:
1896
Catalogue details

Licence: Public Domain Mark

Credit: The air of towns / by J.B. Cohen. Source: Wellcome Collection.

    18/90 (page 10)
    meaHj without knowing it, air with less than 0.07 per cent of carbonic acid. We must not conclude that because tlie quantity ot carbonic acid is small, the effect is small. The conclusion is rather that minute changes in the amount of this acid are indications of occurrences of the highest importance.’’ What is the substance which accomxianies the breath ? Dr. Eansome says that ^‘the aqueous vapor arising from the breath and from the general surface of the body contains a minute proportion of animal refuse matter which has been proved by actual experiment to be a deadly poison. It is this substance which gives the peculiar close, unpleasant smell which is perceived on leaving the fresh air and enter¬ ing a confined space occuified by human beings and other animals, and air thus charged has been fully proved to be the great cause of scrofu¬ lous or tubercular diseases, and it is the home and nourisher of these subtle microscopic forms of lile that have lately become so well known under the title of germs of disease or microzymes. It is probably the source of a large part of that increase of mortality that seems inevitably to follow the crowding together of the inhabitants of towns.” These views are shared by such eminent men as Dr. Foster, Prof. Du Bois- Eaymond, Dr. Carpenter, Sir Douglas Galton, and others. But in what manner has the above statement been put to the ])roof? I desire to refer to a very ingenious experiment which has been car¬ ried out by the French physiologist Brown-Sequard. Fig. 10 represents diagramatically an experiment similar to that of Brown-Sequard. Four bell jars are connected by glass tubes in such a way that by aspirating air through the open tube connected with the fourth bell jar a current of air is made to travel through the series in the direction indicated by the arrows. Between the third and fourth bell jars a vessel is inserted containing strong sulphuric acid, which removes the organic matter from tlie air passing into the last bell jar. By confining mice in these jars, the first mouse will get the fresh aiiy the second will breathe air vitiated by the first, and so on, the last mouse breathing the whole of the carbonic acid given off from the lungs of the first three. In this experiment the third mouse would die, but not the fourth, j)roving that it is the organic poison rather than the carbonic acid in bad air that produces the most serious effects. Whatever may be the exact nature of this poison, of which little more than its mere existence is known, there can be little doubt that the amount in town air, indicated by 0.001 per cent, produces a cumulative effect upon our vitality, which makes us long for fresh country air, and which no doubt enhances the depression induced by the gloom of our city surroundings. Health like charity begins at home, and we should therefore start by studying the conditions under which we live in our own dwellings. Let us consider the case of a person sitting in a room and consuming