DUST AND DAMPNESS. 113 



usual household life they may not do much harm, but we never 

 know when they may become harmful. More attention might be 

 given to getting rid of dust in public halls than is the case. If 

 the sexton dusts a church Sunday morning, the trampling of 

 many feet raises much more from the carpet. 



We now know that the conditions of growth of the dust plants 

 are those of all plant life — warmth and moisture, with the further 

 condition that light is not necessary. It is doubtful whether light 

 is in itself harmful to them, but light places are dryer than dark 

 ones. So, while a certain amount of air is needful, an excess of 

 air is not favorable, — probably because an abundant circulation of 

 air means dryness and often coolness. 



The great question of modern housekeeping is how to protect 

 ourselves from these plant growths, and the answer is, first, not 

 to furnish them food, and, second, not to furnish the conditions 

 of darkness and dampness under which they thrive. Sun and air 

 are our best allies. Dr. Carnelly says, " Cleanliness, both of the 

 person and more particularly of the dwelling or school, is of the 

 ver}' utmost importance in maintaining purity of air as regards 

 micro-organisms, and one which from this point of view has not 

 been previously advocated. Though far from depreciating the 

 beneficial effect of abundant air space, yet we think that the 

 frequency with which the air of a room is changed is a far more 

 important point to be attended to in providing a pure atmosphere." 



Discussion. 



Benjamin P. "Ware said that the remarks of the essayist on 

 cosmic dust and fogs suggested that not only our beautiful sunset 

 effects, but the wonderful after-glow ef the Alps, and possibly 

 the "yellow day" of September, 1881, may all be due to fogs 

 and volcanic emanations. 



Mrs. Richards said that a great advance has been made in the 

 study of beautiful sunsets, after-glows, etc. More attention has 

 been paid to these phenomena since the "yellow day," and 

 especially since those gorgeous "red sunsets" of a more recent 

 date. The investigations which were instituted to discover the 

 cause of the last named manifestations, have satisfactorily settled 

 the question in the minds of the most eminent scientists of both 

 Europe and America. They accept the theory that those brilliant 



