The transmission of infections affecting man has been the object of much thought, theory and conjecture for many centuries. Host to host transfer of infectious agents remained largely in the province of speculation until the "Golden Age of Bacteriology" and the succeeding era of discovery of viruses. In the immediate past half century the experimental method has added considerably to the proposition that certain agents pathogenic to man are transmitted by air.
Well's book is a scholarly treatise on a subject to which he has given earnest consideration for over 20 years, namely, the importance of droplets, droplet nuclei and dust in the spread of infection.