THIS is a very readable work, containing much useful information. As the subject is dealt with in a manner which renders it interesting and easy of comprehension, even to people who may have no acquaintanceship with chemistry and physics, it should appeal to a wide range of readers; but it will prove of special service to the medical student of hygiene and preventive medicine, and the medical writer doubtless had this end mainly in view. The subject of the CO2 respiratory impurity in the atmosphere is treated at some length. In this connection the author states (p. 133) that “Anyone who compares his power of mental work in a pure and in a CO2 laden atmosphere, even if the latter be dry and cool, will find in the latter a considerable diminution, showing that at least nerve metabolism is affected.” This statement implies that the CO2 in a badly-ventilated room (as ordinarily understood) is capable, per se, of producing results which more recent experimental work demonstrates to be due to the combined effects of the altered physical conditions of the air—the increased moisture and temperature, in a stagnant atmosphere. The important subject of the composition, &c., of sewer air is inadequately discussed in eight lines.
Air and Health.
By R. C. Macfie. Pp. vii + 345. (London: Methuen and Co., 1909.) Price 7s. 6d. net.