186 SMELLS AND PERFUMES 



and not exclusively, if at all, on the terminations of the 

 olfactory nerves. An odour that which acts on the 

 special nerves of smell distributed in chambers of the nose 

 acquires its attractive or its repulsive quality only as the 

 result of mental association with what is beneficial (suitable 

 food, mates, friends, safety, home, the nest), or with what 

 is injurious (unsuitable food, poison, enemies, danger, strange 

 surroundings, solitude). Hence it is intelligible that the 

 man accustomed to garlic or onions in his food is strongly 

 attracted by their smell. So too the man whose tribe or 

 companions have learnt by necessity to eat slightly putrid 

 meat, fish, and cheese is attracted by their odour, though 

 for others these odours are associated rather with what is 

 poisonous and injurious. The dislike of the smell of 

 sewer-gas and foul accumulations of refuse was not known 

 to former generations of men (even in European cities a 

 couple of hundred years ago) any more than it is to-day 

 to the more unfortunate poorer classes, to many modern 

 savages, to hyenas, and several other animals and birds 

 which inhabit lairs and caves which they make foul. The 

 odour of putrescence has become actually painful and 

 almost intolerable to the more cleanly classes of mankind, 

 owing to the association with it, as the result of education, 

 of fear of disease and poisoning. Either conscious or 

 unconscious association of an odour with what is held, 

 either as the result of tradition or through personal expe- 

 rience, to be beneficial and of pleasant memory, or, on the 

 contrary, injurious and of painful connection, determines 

 man's liking for, and choice or rejection of, odours and 

 flavours. One can account with fair success on this basis 

 for one's own preferences and dislikes in the matter. 



On the other hand, odours exist in vast variety amongst 

 plants and animals which have not acquired any special 

 association or significance. We find that some organisms 

 produce as a result of their chemical life material which 



