354 



SUMMARY OF OUBRENT RESEARCHES RELATING TO 



suggests a cement which in his opinion will unquestionably serve 

 perfectly well. It is solution of ordinary gelatin in water, coloured 

 slightly with potassic dichromatc. A rather thick solution can be 

 used to make a cell, if used warm on a warm slide. When the mount 

 is finished exposure to light for a short time after tho gelatin is dry 

 renders it quite insoluble. 



Diatoms in Phosphorus.* — L. Dippel finds that all those diatoms 

 which, when niuunted dry, show the markings clearly and sharply, 

 act in the same way in the phosphorus solution, while those (especially 

 GrammatopJiora) for which dry mounting is not suitable, are also 

 badly shown in phosphorus. AmpMpleura pdlucida, Surirella gemma, 

 species of Nitzschia and Pleurosigvia, Naviciila rhomboidea and 

 Frustulia saxonica are best shown in phosphorus ; Grammatophora in 

 monobromide of najihthaline or biniodide of potassium and mercury. 



James' Cover-glass Cleaner.f — F. L. James's device (figs. 92 and 

 93) is especially convenient for cleaning and polishing extremely thin 

 covers. 



Fig. 92. 



Perspective View; 



Fig. 93. 



# * 



Section, 



It consists of three parts : a piece of stout glass tubing, 3 in. to 

 5 in. long and of sufficient internal diameter (7/8 in.) to receive the 

 glass to be cleaned, and two plungers of hard wood long enough to 

 penetrate the tube half-way and leave a good hold for the hands. They 



• Zeitschr. f.Wiss. Mikr., i. (1884; pp. 413-4. 



t Proc. Amer. Soc. Micr., 7th Aun. Meeting, 1884, pp. 181-2 (2 figs.). 



