ORIGIN OF ODOURS.

Putaruru Press, Volume IV, Issue 147, 26 August 1926, Page 3

ORIGIN OF ODOURS.

"THE WAVE LENGTH OF A SMELL. The origin of odours is brought into cujriou® relationship with the formation of colours and. the various phenomena of light, radiant heat, and electricity (hy A. C. Hopper, in The Perfumery and Oil Record). We have long been accustomed, we are reminded, to account for visual imo-g.es in terms of light-waves conducted by nervous impulses to the brain, and, although the physiological prodebs remains quite unexplained, the ■whole matter rests on a scientific basis. “IHtearing-sense and 'sound-waves Show a still more evident relationship, hut even here modern technique has

had ‘to find a way of resolving complex sounds in other component parts and re-constituting them in order to arrive at a more precise appreciation of the physiological factors involved. Sound, patterns of speech, music, and noise have lately acquired? the highest possible importance in psychological and phytHcal examinations. “ It is much more difficult, however, to demonstrate that the phenomena of odours no less than those oif light, occur f2b wave-libe radiations of some hind, perhaps ‘odorantations ’ which are loosed as unsatisfied electrical charges in the collision of atoms in strongly-odorous substances. “ The elements Which yield odorous compounds belong almost exclusively to the fifth, sixth, and seventh groups of 'the periodic classification. Chemically these substances are elements of variable valency. Their unsatisfied linkages s'ct up a movement of val'ency electron -fnich set in motion wave 3 many hundred times shorter than lightwaves, and a frequency many hundred limes as great, which the* nerves of smell r'ecognise as odour.” Mr Hopper suggests'that it ought to hie possible to “ dete.rodyne ” thes-e waves in such a way as to bring them within 'the range o-f the spectroscope, ** thus providing a method of eliminating the “ personal ” ‘element from the investigation of odours and possibly leading to the defection of many odours which come outside the range of the human power of smell.” “ That such theoretical considerations of smell-sense measurements are not without their practical angle is evident from the direction of recent inquiry looking towards the control of the boll-weevil. The pests; are baited by poisons carrying the characteristic odour of the cotton plant, so

attractive to the boll-weevil. “ In connection with the origin of I odours, the formation of colours, and, various other phenomena related to light, radiant heat, magnetism, and I electricity, ilt iis interesting to consider that the odours of certain planes, such as night-scented stock, are hardly noticeable execept after dark, and that , tropical flowers, 'though georgeously ' coloured, are yet devoid of perfume, i Also, a standard method of deod.oriI sation of apparatus for odour experiments is the use of highly-ac/tinic j artificial light. ] “It is interesting, also, 'that many 1 deodorising agents destroy colour dur- | ing the process of deodorisation.- Thus | chlorin and hydrogen period function J both as deodorants and as bleaching | agents. The action of light or chemij cal agents' such as disinfectants cause tha disappearance of what chemists call ' double linkages.’ It is the vibj ratdry action at a double linkage that I Mr Hopper calls the fundamental cause of odour. Mere volatility or /solubility do not account for the various phenomena of odour as they are obs’erved under scientific conditions. “ Many substances exceedingly vola- | tile arous'a no sense of smell. On the : other hand, varying intensiitiesi of odour can he definitely related to the speed of rotation of the valency electrons. Dilute solutions have a somewhat df'rrent odour from what they r have in concentrated states, owing to* the magnetic influence of the mole-

i cults upon one another when crowded 1 I together in the pure substance, j “ A curious practical application of j this principle is cited ty Mr Hopper in 7 the development of a method of utilis--5 ing perspiration in perfumery. It is " I stated that this perfume, of an indif- ' ferent character alone, will in the * presence of perspiration acquire a sweet odour distinctive of the indivi- ’ dual who uses it.” t ■ Soothing ease that woos to sleep, i Warmth that creeps through limb 1 and lung, 1 I Normal breathing smooth and deep, : I Makes it praise by millions sung. L I Coughs and colds are charmed away, And the croup which babes endure, ’ It grows in favour day by day—"l Woods’Great Peppermint Cure. (25) ; I