PHYSIOLOGY OF OLFACTION 43 



only possessed odor but were irritants for mucous sur- 

 faces generally and thus without reference to olfaction 

 could call forth vigorous responses. Magendie, however, 

 claimed that his results were not dependent upon these 

 substances, but could be demonstrated by the use of non- 

 irritants, such as lavender oil. 



Magendie 's opinion that the trigeminal nerve was the 

 nerve of olfaction was opposed almost from the beginning. 

 Eschricht in 1825 pointed to numerous cases of persons 

 who were anosmic in consequence of the absence of the 

 olfactory nerve or of its degeneration. Bishop in 1833 

 described a case of paralysis of the trigeminal nerve in 

 which there was, however, full retention of olfaction. 

 Picht (1829) and Duges (1838), both of whom were incap- 

 able of olfaction in the ordinary sense of the word, were 

 nevertheless easily stimulated through their nasal mem- 

 branes by the vapor of acetic ether, or of ammonia. Val- 

 entin (1839) found that a normal rabbit would sniff the 

 body of a dead one, but that a rabbit whose olfactory 

 nerves had been cut would not thus respond. Schiff 

 (1859) experimented on five pups, in four of which the 

 olfactories were severed, the fifth being retained in a nor- 

 mal condition as a control. After recovery from the op- 

 eration, the four pups in which the nerves had been cut 

 were unable to find the mother's nipples, and did not dis- 

 tinguish between a man and the mother though they 

 turned their heads away and sneezed when ammonia or 

 ether was administered. Acetic acid stimulated them only 

 when its vapor was very concentrated. These and many 

 other similar results completely overthrew Magendie 's 

 contention and showed that, though the trigeminal 

 endings were concerned with the reception of what may be 



