156 THE POPULAR SCIENCE MONTHLY. 



Haroun-el-Raschid to Charlemagne were many perfumes. In the 

 middle ages, among princes and men of highest rank, they washed 

 their hands with rose-water, before and after eating ; some even had 

 fountains from which aromatic waters flowed. At this period, too, it 

 was the custom to carry the dead to their burial-place with uncovered 

 face, and to place little pots full of perfumes in the coffins. The French 

 monarchy always showed an unrestrained passion for enjoyments of 

 this nature, which seemed created as a necessary attendant upon all 

 others. Marshal Richelieu had so extravagantly indulged his passion 

 for perfumes under every form, that he had lost the perception of 

 them, and lived habitually in an atmosphere so loaded with scents 

 that it made his visitors ill. Madame Tallien, coming from a bath of 

 juice of strawberries and raspberries, used to be gently rubbed with 

 sponges saturated with perfumed milk. Napoleon I. every morning 

 poured eau-de-Cologne, with his own hands, over his head and shoul- 

 ders. 



IV. 



Above all these questions which we have just skimmed, there rises 

 another, of a graver and more mysterious kind, one which occurs at 

 the end of all studies that treat of sensation, and with regard to which 

 some reflections will not be out of place here. To what, outside of us, 

 do those sensations which we experience within us correspond ? What 

 relation is there between the real world and that image of the world 

 shadowed in our soul ? In the special case we are concerned with, 

 what is it in these substances which is the cause why they affect our 

 sense of smell ? It seems certain, in the first place, that odor in itself, 

 so far as it is odor, is a mere figment of our mind. Contemporaneous 

 physiology proves that excitement of the nerves of sensation is fol- 

 lowed, in each one, by the sensation that corresponds with each. 

 When we electrify the eye, we call up in it an appearance of light ; 

 when we electrify the tongue, we produce in it a sensation of taste ; 

 when we electrify the inside of the ear, we provoke in it the effect of 

 a sound. So, too, a similar excitement, electric or otherwise, of the 

 olfactory nerves, creates in our mind the sensation of smell, even 

 though no odorous molecule takes part in the phenomenon. Sensa- 

 tion, therefore, seems to depend chiefly on the nature of the sensitive 

 nerve. The external world seems to contribute to it only by setting 

 in motion the nerve-fibres. Even this condition of an impulse imping- 

 ing from without is not indispensable, since, in sleep and in madness, 

 we experience sensations of smell which, by the testimony of our other 

 senses, answer to no external agent. Still, we believe that we can 

 distinguish cases of hallucination from cases of true perception ; still, 

 we maintain that there are, outside of ourselves, distinct causes of our 

 distinct sensations. No skepticism has prevailed, nor will prevail, 

 against this testimony of the most powerful evidence which exists in 



