PHOTOMICROGRAPHY* HARRY T. BAncLaY. GETTY~BURG COLLEGE, G E ~ ~ Y S BPENNSYLVANCA ~RG,
To those who are interested in photomicrography and who read Mr. A. G. Moseley, Jr.'s article in the July, 1931, issue of the JOURNAL OF C H E ~ C AEDUCATION L (pp. 1359-63), 1 suggest the following means of taking photomicrographs if a small camera is not available. Procure a large bellows, from a photographer's camera if possible; the larger the beilows the greater will be the magnification. Clamp the bellows in an npPlate holder right position to a stand, nail a piece of Adjustable bellows pliable leather over the lower end of the bellows and cut a hole in the center having a diameter equal to that of the eyepiece of the microscope. Insert the microscope beneath the bellows so that the eyepiece fits tightly in the hole just made. If this is made correctly t h e bellows is now lighttight. Bore a hole in a desk (which is enclosed on all sides), and clamp a 100-watt lamp on another stand , , in the desk. T h e 110-volt Light source in light will now pass desk below microscope throurh the micro" scope and bellows, and the image of the object to be photographed is projected upon the ground glass a t the top of the bellows and can be focused as desired. The apparatus must be light-tight throughout, and all precautions must be taken to keep photographic plates from light. The developing of the plates can follow the procedure as given in the "Handbook of Chemistry and Physics," Chemical Rubber Publishing Co., any edition. 'Presented before the "Skeptical Chymists" at Gettysburg College, March 30, 1931. 2425
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JOURNAL OF CHEMICAL EDUCATION
SODIUMCHLORIDE CRYSTALS PROM SOL~ION EVAPOKATED ON GLASS SLIDE
DECEMBER, 1931
POTASSIUMCHLORIDECRYSTALS SOLUTION EVAPORATED ON SOLID SODIUM CHLORIDE, SHOWINO ORIENTAFROM
TION
Many of the crystals which the author has photographed were made by evaporating a drop of solution on a grease-free glass slide. A difference was noticed in many cases when the initial concentration of the solution was changed.
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I wish to add a word of appreciation to Dr. C. A . Sloat, professor of fihysical chemistry, Gettysburg College, who has permitted me the use of his laboratory and materials, and who has encouraged me at all times.
