THE DANGERS OF INHALED DUST

In a widely circulated popular book, entitled "Dust and Its Dangers," which was published about thirty years ago, emphasis was placed on the distribution of bacteria by that form of "matter out of place" which is commonly designated as dust. This was quite appropriate at a time when the widespread distribution and previously unsuspected significance of the micro-organisms were being brought to the notice of the world at large. Since that early period in the development of modern bacteriology, preventive medicine has begun to direct attention to quite different aspects of the dust menace. The recognition of the possible pathologic effect produced by the inhalation of minute, nonliving particles of matter is by no means new. Clinical observations on the subject have long been on record; and the question as to whether certain pigmentations of the lung are due to extraneous particles or to pigmented tissue products has been debated