1898J MICROSCOPICAL JOURNAL. 13 



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

 This silk stands only three months steady wear. 



Effectiveness 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 mag-niJ&cation and resolving- 

 power than to angular aperture. 



Enlarg-ing- photog-rag-hs does not help us for there is 

 nothing- of detail in the enlarg-ement that was not in the 

 orig-inal. If new details are to appear, they must be 

 secured by enlarg-ing- 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 thoug-ht of slicing up a blood-cell except 

 Elmer Gates. He also sections microbes. Cement on a 

 gflass slide a sing-le 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 edg-e that razors are incapable of re- 

 ceiving-. Use adamantine paper upon a g-lass 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 ag-ain 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- 



