PRACTICAL PHOTO-MICROGRAPHY. 45 



impaled with a short length of platinum wire, and then gradu- 

 ally dried, first in a heated iron oven, then in coal gas flame, 

 lastly in the oxy-hydrogen flame, as suggested by Dr. Roux of 

 Paris ; but the result seemed decidedly inferior to the ordin- 

 ary lime. Zirconium oxide was also tried with no better 



success. 



FIG. 12. SWIFT' MICROSCOPE LAMP. 



Probably most of our readers will find an oil lamp answer 

 all desired purposes, and if time be no object, a good oil lamp 

 will probably prove entirely satisfactory. If the wick be 

 single and flat, and if it can be turned either broadside or edge 

 to the microscope, the kind of lamp is practically immaterial. 

 But lamps are made specially for this work and several of 

 them may safely be recommended. Mr. Swift's lamp (fig. 12), 

 for instance, has served the writer thoroughly well, and the 

 lamp figured ~No. 13 is also well adapted for this work. 



