4 THE WORLDS LUMBER ROOM. 



cannot therefore be wholesome to have it about us, as, 

 though the exact nature of the germs which spread scarlet 

 fever and other diseases may not be determined, one thing 

 is certain, namely, that they flourish most in the neighbour- 

 hood of dirt ajid decaying matter of all kinds. 



The lighter part of this dust floats in the air, as we 

 see whenever a sunbeam shines into the room and reveals 

 it to us; the heavier settles on the floor and furniture, 

 where, in towns at least, it is so blackened by dust of 

 another kind the smoke and soot arising from the imper- 

 fect combustion of fuel that it is not easy to tell what its 

 original colours were. 



Still, the examination of any bit of " flue " which has 

 collected behind some piece of furniture too heavy to be 

 constantly moved, will show us that it consists in the 

 main of fine hairs and particles of wool, worsted, cotton, 

 &c., which have been worn off by the housemaid's" broom 

 and our own movements, and felted together by pressure, 

 some being large enough to show their origin plainly, 

 while others are mere dust, scarcely distinguishable as 

 hairs at all by the naked eye. 



But besides the dust made inside the house, some of 

 that made outside also finds its way in, and in dry, windy 

 weather covers the furniture with a very unpleasant gritty 

 film ; for it is so exceedingly fine that, like very fine snow, 

 it will make its way through the smallest cracks and 

 crevices, and is not to be kept out by closed windows. 



In towns, much of this dust also is made by rubbing 

 and friction. The wear and tear occasioned by the in- 

 cessant passing of feet and the wheels of heavily-loaded 



