THE MICROSCOPE. 



121 



cases: may they not be caused by similar substances? Does any 

 one, for example, know whether the sharp-faced crystals of calcium 

 oxalate which are found so abundantly in rhubarb, are dissolved in 

 passing through the alimentary canal? We do know that rhubarb is 

 reckoned among the predisposing, if not actually exciting causes of 

 haemorrhoids. 



{Barker.) 

 "PEAR GRITS" /. e., STONE OR SCLERENCHVMA CELLS FROM THE 

 PEAR. CLUSTERS MAGNIFIED ABOUT 200 DIAMETERS. 



The subject is especially commended to the attention of the 

 profession in the country, where observation in this direction will 

 doubtless show that the case above instanced is by no means a 

 solitary one. 



I am indebted to my friend and pupil, Thomas Ridgway Barker, 

 for the illustration which accompanies this article. — Medical and 

 Surgical Reporter. 



