Physiology. "/s there any Relation hetioeen the Capacity of 

 Odorous Substances of Absorbing Radiant Heat and their 

 Smell- intensity .'^" Hy Dr. G. Grijns. 



(Communicated in the meeting of September 2'-', 1918). 



For a tlioroiigh knowledge of the ai)percej)tion of our senses we 

 must first of all find out the special character of the stimulus to 

 the receiving of which the organ is adapted. The studj' of light and 

 sound teaches us tliat the quality' is determined by wavelength, and 

 its intensity by amplitude. Witli regard to smell and taste we do 

 not know as yet what property of the odorous or the gustable 

 substance determines the sensations they arouse. 



Many attempts have been made to establish a relation between 

 smell and certain qualities. Up to the juesenl without success. 



The chemical properties which, indeed, were thought of first and 

 foremost, ap|)eai'ed to yield no satisfactory interpretation of all the 

 peculiarities. Zwaardemaker ^), therefore, reaches the conclusion in 

 his "Physiologic des Geruchs", that no direct relation exists between 

 the chemical constitution of a substance and its smell. 



LiÉGEOis") pointed out that a large number of odorous substances, 

 when put on tiie surface of clean water, |)resent the same phenom- 

 enon as Prevost') described for camphoi- and even calls it the 

 "odoroscopic phenomenon". However, it turned out that a number 

 of inodorous substances also present this phenomenon. So there is 

 no argument for correlating smell with surface-tension phenomena, 

 to which VAN Mensbrugge attributes the behaviour of camphor on 

 water. 



Zwaahdemaker's finding^) that a large number of odorous substances 

 evolve an electrically charged vapoui', when spi-ayed in aqueous 

 solution, gave rise to the supposition, that electrical charges come 



1) H. ZwAARDKMAKEB, Die Physiol.ogie des Geruchs. Leipzig 1895. 

 ') LiÉGEOis : Sur les mouvements de certains corps organiques a la surface de 

 I'eau. Arch, de Physiol. 1868 T. I p. 35. 

 ^) Prévost: Annales de Ghimie et de physique XXi p. 254, XXIV p 31, XL pi. 

 *) H. ZwAARDEMAKKR, These Proc. XIX p. 41, 334 and 551. 



