LIEBERKUHN'S CONDENSER. 



13 



83 



Fig. 46. Condenser and Table-lamp. 



centre of the Lieberkuhn ; but in the lower powers, where 

 a great amount of reflecting sur- 

 face would be lost on account 

 of the large size of the glasses 

 employed if this plan were 

 adopted, the aperture in the 

 centre of the Lieberkuhn is 

 made to admit as many rays as 

 will fill the field of view, and no 

 more. 



Lamps. The achromatic gas- 

 lamp, fig. 48, is the best and 

 most economical. 1 Gas, as a 

 source of light, presents great 

 advantages over oil and spirit, 



.on account of cleanliness, being 

 (1) Matthews, of Portugal Street, supplies lamps, condensers, and other articles 

 useful to the raicroscopist. 



G 2 



Fig. 47. 



