1898J MICROSCOPICAL JOURl^AL. 13 



tion is with tin. It is in the "weig-hting-" of the silk. 

 This silk stands only three months steady wear. 



EfEectiveness of the Microscope. — The ang-ular aper- 

 ture of objectives has been increased about all that it is 

 likely to be. We shall hereafter look more to the utiliza- 

 tion of shorter wave-leng-ths of the invisible ultra-violet 

 rays for improvements in magnification and resolving- 

 power than to angular aperture. 



Enlarging photog-raghs does not help us for there is 

 nothing of detail in the enlargement that was not in the 

 original. If new details are to appear, they must be 

 secured by enlarging- the imag-e before it is photographed. 

 That is what Gates claims to have succeeded in doing. 



Microtome Work Outdone. — The limit of thinness cut 

 by the microtome has been about 2-1000 of a millimeter. 

 No one has ever thought of slicing- up a blood-cell except 

 Elmer Gates. He also sections microbes. Cement on a 

 glass slide a single layer of cells. Then cement another 

 glass slide to that. Cut the two apart with a very thin 

 blade of copper the edg-e of which has first been sharpened 

 to the finest degree possible. Copper being finer grained 

 than steel takes an edge that razors are incapable of re- 

 ceiving. Use adamantine paper upon a glass surface as a 

 whetstone. A still finer edge is got by polishing it with 

 a piece of soft wood. Get the edg-e exactly in the middle 

 between the two surfaces on the copper plate. 



The cells having- been once sliced are again cemented to 

 glass and cut open once more. Gates has made slices 

 1-lOOth the thickness of the thinest ever made with micro- 

 tomes. 



Yellow-Fever Prize.— Brazil offers $200,000 for a dem- 

 onstration of the bacillus of yellow fever, the surest and 

 easiest means of its recognition, and an effective means of 

 treatment. It purposes to build a laboratory for prepar- 

 ing curative serum as soon as that serum is discovered. 



Bromine Sterilization. — To each litre of water add .06 

 gram of bromine, then in 5 minutes ammonia to neutral- 



