ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 



487 



paraffin oil, in whicli is dissolved a lump of camphor of the size of a 

 walnut to the ordinary reservoirful ; this whitens the flame and renders it 

 more actinic. A plano-convex lens, with the convex side towards the 



Fig. 143. 



flame, concentrates the light on the object. A curtain of black velvet B 

 falls over the front of the box, shutting all light in, and a shutter cuts off 

 the rays coming through the objective till all is ready for them to fall on 

 the sensitive plate. 



DagTon's Microphotographic Apparatus.* — M. Dagron's apparatus for 

 producing microscopic photographs (first used for pigeon despatches during 

 the Franco-German war) is shown in figs. 144 and 145). 



It consists of a long rectangular chamber closed at A by ground glass 

 which is brightly illuminated from outside and on the inside of which is 



Fig. 144. 



a clamp to hold the negative to be reduced. At the other end of the 

 chamber is the photographic apparatus. At B is a set of 20 microscopic 

 objectives arranged in rows of five, which project images upon a very finely 



* S. T. Stein, ' Das Mikroskop und die mikrograpliisclie Teclinik zura Zwecke 

 photographisclier Darstellung,' 1884, pp. 315-20 (3 figs.). 



