46 SMELL, TASTE, ALLIED SENSES 



the head of a human cadaver in the median plane, replaced 

 the nasal septum with glass and by means of an artificially 

 produced respiratoiy current showed that smoke in its 

 passage through the nasal cavity remained in the so-called 

 respiratory region. He observed, however, that both in- 

 spiration and expiration were accompanied by strong 



Fio. 12. Diagram of the right nasal cavity of man laid open and showing by arrows the 

 direction of the inspired current of air over the nasal septum (right half of figure) and over 

 the lateral wall (left half of figure). After Paulsen, 1882. 



eddies in the moving air. Kayser (1890) aspirated very 

 light magnesia powder into the respiratory current of a 

 quietly breathing normal subject and then inspected the 

 nasal surfaces by means of a rhinoscope. The magnesia 

 particles accumulated on the moist surfaces of the respir- 

 atory portions of the nose and not on those of the olfac- 

 tory region, thus confirming Paulsen 's results but by a 

 method that was by no means so artificial as that employed 

 by other workers. It may, therefore, 'be regarded as 



