THE DUST WE HAVE TO BREATHE. 



A MICROSCOPIST, Mr. Dancer, F.B.A.S., has been ex- 

 amining the dust of our cities. The results are not 

 pleasing. We had always recognised city dust as a 

 nuisance, and had supposed that it derived the peculiar 

 grittiness and flintiness of its structure from the con- 

 stant macadamizing of city roads. But it now appears 

 that the effects produced by dust, when, as is usual, it 

 finds its way to our eyes, our nostrils, and our throats, 

 are as nothing compared with the mischief it is calcu- 

 lated to produce in a more subtle manner. In every 

 specimen examined by Mr. Dancer animal life was 

 abundant. But the amount of 4 molecular activity ' 

 such is the euphuism under which what is exceedingly 

 disagreeable to contemplate is spoken about is vari- 

 able according to the height at which the dust is 

 collected. And of all heights which these molecular 

 wretches could select for the display of their activity, 

 the height of five feet is that which has been found to 

 be the favourite. Just at the average height of the 

 foot-passenger's mouth these moving organisms are 

 always waiting to be devoured and to make us ill. 

 And this is not all. As if animal abominations were 

 insufficient, a large proportion of vegetable matter 

 also disports itself in the light dust of our streets. 

 The observations show that in thoroughfares where 

 there are many animals engaged in the traffic, the 

 greater part of the vegetable matter thus floating about 



