ANIMALS. 49 



Indeed, if we examine the natives of different 

 countries, or even different natives of the same, 

 we shall find no pleasure in which they differ so 

 widely as that of smelling. Some persons are 

 pleased with the smell of a rose ; while I have 

 known others that could not abide to have it 

 approach them. The savage nations are highly 

 delighted with the smell of assafcetida, which is 

 to us the most nauseous stink in nature. It 

 would in a manner seem that our delight in per- 

 fumes was made by habit, and that a very little 

 industry could bring us totally to invert the per- 

 ception of odours. 



Thus much is certain, that many bodies which 

 at one distance are an agreeable perfume, when 

 nearer are a most ungrateful odour. Musk and 

 ambergrise, in small quantities, are considered 

 by most persons as highly fragrant; and yet, 

 when in large masses, their scent is insufferable. 

 From a mixture of two bodies, each whereof is, 

 of itself, void of all smell, a very powerful smell 

 may be drawn. Thus, by grinding quick-lime 

 with sal-ammoniac, may be produced a very fetid 

 mixture. On the contrary, from a mixture of 

 two bodies, that are separately disagreeable, a 

 very pleasant aromatic odour may be gained. A 

 mixture of aquafortis with spirit of wine produces 

 this effect. But not only the alterations of bodies 

 by each other, but the smallest change in us 

 makes a very great alteration in this sense, and 

 frequently deprives us of it totally. A slight 

 cold often hinders us from smelling ; and as 

 often changes the nature of odours. Some per- 



VOL II. D 



