16 ON THE ACTION OF TRANSPARENT BODIES 



It exercises almost the same (perhaps a little greater) action 

 upon green light, as oil of cloves. 



58. Nitrate of Potash. 



The refractive force which produces the greatest refraction 

 in this salt, acts much less powerfully upon green light than 

 -crown-glass, and a little less powerfully than fi hit-glass. 



59. Nut Oil 



Nut oil acts less powerfully upon green light than crown- 

 glass. 



When it acts in opposition to flint-glass, no secondary spec- 

 trum is visible. 



It acts more powerfully upon green light than oil of marjo- 

 ram. 



60. Nutmegs, Oil of. 



This oil acts less powerfully upon green light than crown- 

 glass, and a very little less than flint-glass. 



61. Olives, Oil of. 



Oil of olives acts less powerfully upon the green rays than 

 crown-glass, and a very little less than flint-glass. 



62. Pennyroyal, Oil of. 



This oil acts much less powerfully upon green light than 

 crown-glass, and considerably less than flint-glass. 



63. Peppermint, Oil of. 



Oil of peppermint acts less powerfully upon the green rays 

 than crown-glass, and a little less powerfully than flint-glass. 



64. Poppy, 



