CONTENTS. xiii 



CHAPTER ni. 



Page 



AccESsoBY Instruments 110 



The diaphragm - - - 111 



Dark chamber - - 112 



WoUaston condenser - it,. 



Achromatic condenser - . 113 



Mr. Wenham's illuminator - -116 



Prism of Dujardin - - 118 



Achromatic prism - - - Hi) 



Oblique prism - ib. 



Polarizing apparatus 120 



Condensing lens - - - 122 



Erector - - 125 



Lieberkuhn - 126 



Side reflector . 127 



Dark stops or wells 128 



Forceps - ib. 



Animalcule cages - ] 30 



Fishing tubes for animalcules ■■ 1 33 



Compressorium - - 137 



Troughs for chara and polyps - - 140 



Frog-plate - - 141 



Fish-troughs - - - 142 



Phial-holder - 143 



Camera lucida - - - 144 



Indicator - - - - 145 



Bonnet or hood for the compound body - 147 



CHAPTER IV. 



The Lamp - 149 



Chimney shade - - 153 



Oil 154 



Jatropha oil - ib. 



Cleaning lamps ... ib. 



Portable candle-lamp _ _ 155 



To clean chimneys of lamps 158 



CHAPTER V. 



On the Magniftikg Powebs used with Simple and Achro- 

 matic Compound Microscopes - 158 



