Show MANS MAN'S NOSE SENSITIVE ORGAN How Extraordinarily Minute Particles in Air at Once Affect the Ol- Ol Olfactory Olfactory factory Nerve Do loy Y you ti know Wll why you ou have ha to sniff snit the time air 1111 when tJ trying to tn detect a faint oror odor It IF Is because se the time nerves nel governing govern go ing the i ense sense of smell are cot Got located as HS is generally supposed ed in iii the nasal rO passages but hut In in Inan an area of sensitive membrane about the size of II a litHe dime and locater located high above e each ench nostril 4 A portion of r the hairlike tips of If the time olfactory nerves ner terminating In this membrane receives receive the sense sene Imprecision slon sion and amid conduct conducts it to time tile brain Because Because Be cause of ot the position of ot this membrane outside tho the natural path of the time breath It Ills is necessary to draw n aside a current of at air dr by sniffing before the exact shade of odor can be lie determined The effects of ot snuff and smelling salts nothing to do with the time sense of ot smell They react only on the lInings linings lin tin ings of tho the nasal passages I So far tar as physiologists have been uhle to learn leant smells arc pigeonholed In the brain as ns visual impressions Each goch smell carries associations good or ball bail and these associated hua Images es mire are bi might forth by the time brain when particular par par- nerves are excited The reaction of ot thiS the brain to an odor depends also to a large extent on the sn sense e of nC taste Only by br combining the time brain reports of these two senses en es can cnn odors be accurately catalogued as the olfactory nerve nerves s sense nse In man JUnn has become through evolution eve evo lution it still retains the marvelous ma ability to detect one part of ot camphor In four hundred thousand parts of air nil one part of or vanillin in ten million parts of nil nir As for the obnoxious smell the human nose can detect th presence or of one part Int In hi t twenty five trillion parts hurts of ot air Popular Inc lar Science Monthly |