1686 



Journal of Applied Microscopy 



Note on Photographing Fruits. 



Having occasion to make some photographs of apple to show the location of 

 starch at certain stages of ripening of the fruit, the cut surface was covered with 

 iodine solution by allowing to stand in a watch-glass of iodine in potassium iodid 



solution. As some little time 

 was required for the penetratior> 

 of the iodine solution, there 

 occurred considerable coloring- 

 brown in the non-starchy por- 

 tion, which was not improved 

 by allowing the iodine solution 

 to evaporate on exposure to the 

 air since then the counter stain- 

 ing by oxidation set in. 



Contrastive effects, however^ 

 were obtained by covering the 

 freshly cut specimen with a bell- 

 jar underneath which was burn- 

 ing a pinch of sulphur. It was 

 left for sixty to ninety seconds (a longer exposure interferes with the subsequent 

 iodine staining), rinsed thoroughly in water, dipped under iodine solution till a 

 good stain has been obtained, washed and exposed to the air thirty minutes or 

 until the brown color due to the iodine solution has disappeared. In this 

 manner good specimens for photographic purposes were obtained, in which the 

 non-starchy portions were nearly white. The accompanying print shows the 

 retention of starch in bruised parts, while in the normal portion the last traces 

 are located in the peripheral region and adjacent to the fibrovascular bundles. 

 U. S. Dept. of Agri., Bureau of Chem. BuRTON J. HoWARD. 



Photograph of apple showing (a) location of starch 

 in bruised spots. 



ELEMENTARY MEDICAL MICRO-TECHNIQUE. 



For Physicians and Others Interested in the Microscope. 



Copyrighted. 



III. PNEUMOCOCCUS, Croupous Pneumonia. 



As a safeguard to the diagnosis a second preparation should be stained by- 

 Gram's method, as follows : Stain twenty minutes with gentian violet and transfer 

 without washing to the decolorizing mixture : 



Iodine, 1 gram. 



Potassium iodide, . . . . 2 grams. 



Distilled water, - . . . 300 c.c. 

 which should act for about fifteen minutes ; rinse thoroughly in alcohol. If any- 

 violet color remains decolorize again, rinse in alcohol, dry, and mount in balsam 

 as described above. 



