222 BERTHA'S VISIT TO HER 



middle one being inverted, and the two others 

 erect. 



Dear mamma, how this reminded me of the 

 day when you first explained to us the meaning 

 of refraction, and shewed us the pretty little 

 experiment of the stick, which appeared to bend 

 just at the surface of the water. How often I 

 now feel the benefit of all your patient instruc- 

 tion, and how often I wish I had your excellent 

 memory, which enabled you to teach us so many 

 things, without having any books to assist you I 



20th. My cousins like Eastern tales just as 

 much as I do and my uncle speaks of the 

 Arabian Nights' Entertainments as if he was still 

 a boy. He thinks that they are not only very 

 ingenious, but that many of the apparent won- 

 ders, which are related as supernatural, may be 

 easily explained, by means of the chemical and 

 philosophical knowledge which is too generally 

 supposed to be the result of late discoveries. I 

 should like to read over all my favourite tales 

 with him, for the benefit of his explanations. 

 What brought them into my mind now, was a 

 pretty little anecdote which I once heard him 

 tell Grace, and which she has just been repeating 

 to me. 



In Khorasan, there was a certain old caravan- 

 serai, called Zafferounee, which was once so 



