Achromatic Oondensor. 



Higher eye-pieces are, however, useful in testing an 

 object glass, as very many of those sold, while giving 

 fairly good results with a no. 1 eye-piece, become blurred 

 and indistinct when a no. 3 or 4 is used. 



Illumination. Daylight is the best light to use for 

 Histological work, and in the summer time there is 

 generally enough light for ordinary work. In the win- 

 ter, however, a lamp is often required even in the day- 

 time, as there are many days when sufficient light 

 cannot be obtained. 



It is necessary, therefore, to be provided with a lamp 

 burning either gas or parafine oil. The best gas lamp 

 is made by Baker, it is a modification of the Highley 

 microscopic lamp and is fitted with a Sugg's burner, it 

 will be found very useful. An ordinary parafine lamp 

 which can be purchased for 2s., with a f inch flat wick, 

 will be found all that is necessary by those who do not 

 wish to get the more expensive gas lamp. It has also 

 this advantage, the wick being flat the edge of the flame 

 can be turned to the microscope, giving an intensity of 

 light very useful in the investigation of fine structures 

 under very high powers. 



ACHKOMATIC CONDENSER. 



A SMALL condenser made to go into the fitting under the 

 stage will be found very useful, but for high power work 

 with a large stand a wide angled condenser is necessary, 

 having a series of stops for oblique light, and a graduated 

 diaphragm by which the rays of light can be gradually 

 cut off until the best definition is obtained. 



