It will scarcely be contended that the air-passages, though perhaps the most important, constitute the sole channel through which tuberculosis is acquired. Volland1 calls renewed attention to an additional mode of transmission, which is applicable both to tuberculosis as such and also to scrofulosis. He points out that the latter affection is essentially a disorder of childhood, not appearing until after the first, and prevailing largely until the fifth year, thereafter diminishing in frequency; and he relates this distribution of the disease to infection conveyed through the hands soiled in creeping and playing on the floor, and the like. The scrofulosis thus acquired may become manifest, or it may remain latent, perhaps to break out later in life, under suitable conditions, as tuberculosis. Whether this explanation is applicable to a large number of cases or not, the prophylactic measures that it suggests should not be ignored or neglected, namely,