878
��Popular Science Monthly
��Why a Featherduster Is Like a Fly
ANYBODY can see a feather duster in the hands of the housekeeper, but it takes a microscopist to discover that the fly uses a similar duster in the characteristic and amusing performance known to children as "fiddlino^." From its own viewpoint the house-fly is neat
���With these featherduster - Hke legs, the fly spends much of his time freeing himself from particles of dust
��and cleanly, but it cares not where it scatters its dust, nor how much it in- conveniences and menaces human be- ings. The fly dusts its body with praise- worthy industry and continuity, passing one leg over the other with a peculiar rolling motion, using each like a feather- duster, and the leg being dusted as an- other duster.
Under the microscope, the legs, not only of the house-fly but of others re- lated to it, are seen to be covered with hairs and bristles, which under low pow- er, give the entire leg a feathery ap- pearance. In some flies even the termi-
��nal claws are hairy. The fly is evidently annoyed by the dust, and much of its spare time seems to be devoted to the fiddling process. A microscopist who wants to prepare a fly for microscopical study usually allows it to develop under a bell glass, or in some other condition in which the dust cannot soil the speci- m e n. The accompanying illustration of a fly's fiddling legs show, even under the highest power of the micro- scope, not the slightest par- ticle of dust, because the fly was prepared immediately after such transformation. The purpose of the picture is to display the feathery legs in their fiddling posi- tion, free from dust. The freedom from dust is, in this instance, due to the skill and ingenuity of the micro- scopist, not to the diligence of the fly.
The moral of the picture : A feather duster in the hands of a diligent house- maid can spread more dis- ease germs than a hundred flies with their microscopic feather dusters, and the mechanism is the same. Campaigns against the fly should include the duster- wielding housewife. Pla- cards should be exhibited with pictures of a fly and a house- wife and with this legend: "These two animals spread disease with their feather- dusters."
��Paraffin Protects the Labels of Chemical Bottles
IF the amateur chemist will paint a thin coating of parafiin over the la- l)els of his reagent bottles with a fine brush he will be saved much time and bother in replacing labels. The paraffin will prevent any drops of reagent from attacking and badly discoloring the la- bels. Most reagents do not act on paraf- fin. The paraffin coating should extend about one-quarter of an inch beyond the edges of the label.
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