17^ THE PHILOSOPHY 



ceedingfrom hemlock, and from many other noxious vege- 

 table, animal, and mineral fubftances, are highly ofFenfive to 

 om- noftrils. Hence we are naturally compelled to embrace 

 the one clafs of fenfations and to avoid the other. 



Some animals, as the dog, the fox, the raven, Szc. are en- 

 dowed with a moft exquifite fenfe of fmelling. A dog 

 fcents various kinds of game at confiderable diftances ; and, 

 if the facSl were not confirmed by daily experience, it could 

 hardly gain credit, that he can trace the odour of his maf- 

 ter's foot through all the winding flreets of a populous city. 

 If we judge from our own feelings, this extreme fenfibilitjr 

 in the nofe of a dog is to us perfectly incompreheniible. 



The fenfe of fmelling, like that of fome other fenfes, may 

 be perverted or corrupted by habit. The fnuffing, chew- 

 ing, and fmoaking tobacco, though at firft difagreeable, be- 

 come, by the power of habit, not only pleafant, but almoft 

 indifpenfible. The fame remark is applicable to the practice 

 of fwallowing ardent fpirits, the moft deleterious of all poif- 

 ons, becaufe the moft extenlively employed. How the nat- 

 ural ftate of the nerves, and of the fenfations conveyed by 

 them, fhould be fo completely changed, we are totally ignor- 

 ant. The conftitution of the nerves often varies in diifer- 

 ent individuals of the fame fpecies. An odour which is dif- 

 guftful to one man is highly grateful to another. I knew a 

 gentleman who was in the daily habit of lighting and put- 

 ting out candles, that he might enjoy the pleafure of their 

 fmell. Fev/ men, I fuppofe, would envy him. 



OF TASTING. 



THE tongue and palate are the great inftruments of this 

 fenfation. With much wifdom and propriety the organ of 

 tafte is fituated in fuch a manner as enables it to be a guar- 

 dian to the alimentary canal, and to aflift the organ of fmell 

 in diftinguifhing falutary from noxious food. The tongue^ 



