HANDBOOK OF PHOTOGRAPHY 



Thus it became possible to photograph most living material at very high powers 

 (1200 to 3600 diameters), to take optical sections on planes spread i^ m apart, and to 

 avoid many of the artifacts which have perplexed cytologists. Cytological studies 

 soon demonstrated that some of the details of structure attributed to cells on the basis 

 of fixed and stained material did not appear to be present in the living cell. As a tool 

 for biological research the ultraviolet microscope offers far-reaching possibilities, 

 notwithstanding the fact that a more precise technique is required than for the visible- 

 light microscope. 



In science and industry it has much to offer. High resolving power and the 

 characteristic crisp, brilliant images obtained make it possible to photograph very 



— MICROSCOPE — 

 A- SEARCHER EYE PIECE OR ARTIFICIAL EYE 

 B- QUARTZ OCULAR • 

 C- QUARTZ OBJECTIVE 

 D- SPECIMEN ON QUARTZ SLIDE 

 E- GLYCERINE IMMERSION FLUID WHEN 

 HOMOGENEOUS SYSTEMS ARE USED 

 F- QUARTZ SUB-STAGE CONDENSER 

 G - FRONT LENS OMITTED WHEN DRY SYSTEM (6-MM. 

 OBJECTIVE) IS USED. INTERCHANGEABLE FRONT 

 LENSES EMPLOYED FOR HOMOGENEOUS IMMERS- 

 ION SYSTEMS (2.5-MM. AND l.7-MM,0BJECTIVES) 



H- URANIUM GLASS SCREEN MOUNTED IN RING OF 

 SUB-STAGE IRIS FOR CENTERING ILLUMINATION; 

 SWUNG OUT OF POSITION WHEN MICROSCOPE IS IN USE 

 J- QUARTZ PRISM 

 K- WINDOW IN SIDE OF MICROSCOPE BASE 



^ 



'^^ 





X275/UJJL 



ULTRA-VIOLET LIGHT 

 — GENERATING EQUIPMENT — 

 L- IRIS DIAPHRAGM 

 M- QUARTZ PRISMS 

 N— COLLIMATOR 

 P- QUARTZ SLIT 

 Q- CADMIUM SPARK ELECTRODES 



mx 



I 



N <±> 



•\|/ 



Fig. 17.- 



Q 

 -Diagram illustrating optical systena of ultraviolet microscope. 



small particles such as pigments, fillers, etc. Organic compounds such as soaps, oils, 

 fats, waxes, etc., can be studied in the same manner as tissue preparation. Problems 

 in catalysis, adsorption, filtration, etc., are open to study as never before, and the 

 deposition of metallic salts and compounds can be traced and detected oftentimes to 

 far better advantage than bj^ anj^ other means. In a system in which two or more 

 phases are present, selective absorption differentiates the phases and enables one to 

 trace their origin or history through manufacturing or production cycles. Under 

 favorable conditions particles of matter which measure only a few hundred atom 

 diameters across can be clearly photographed. When absorption is strong, resolution 

 can be extended downward to about 200 atom diameters. In the colloidal state of 

 matter the ultraviolet microscope has provided the means to secure real images, not 

 diffraction effects of the submicrons. Photographs of these bodies may be analyzed 

 mathematicallj'' as one might the photograph of coarse pigments and fillers. From the 



