60 THE AMERICAN MONTHLY [Feb 



breaks the yeast cells into fine particles but if any are left 

 unbroken the microscopical examination shows that the 

 liquid contents are gone. This powdered mass will never- 

 theless produce fermentation, which proves erroneous the 

 hitherto held theory that perfectly org-anized and living- 

 cells are necessary to fermentation. The cell-life has van- 

 ished. If life is there it is in the particles. The chemists 

 say the action is due to the chemical power of an amylolyte 

 acting in a manner similar to digestive ferment, but they 

 cannot yet isolate the fermentative enzyme. 



New Periodical. — Messrs Lund & Company, Amen cor- 

 ner, E. C, London have issued an Illustrated Annual of 

 Microscopy devoted to the progress made in research and 

 the newest devices in apparatus and methods covering 

 photo-micrography, bacteriology, technic of mounting, 

 pond-life and the theory of micro-optics. Among the con- 

 tributors are Van Heurck, Cole, Hartog, Beck, Karop, 

 Soar, Spitta, each upon his speciality. The price is one 

 dollar if ordered through us. We shall reproduce its most 

 most valuable features from time to time. 



MICROSCOPICAL APPARATUS. 



Bacteriolgoical Laboratory. — In Yokohama there is a mi- 

 crobe-proof house built of glass blocks. There are no win- 

 dow-sastjes. The closed doors are air tight. A pipe con- 

 taining cotton-wool filter admits the air partly purged of 

 bacteria. It is further sterilized by being driven against 

 glycerine-coated plate-glass. The house is flooded with 

 sunlight which still further destroys micro-organic life. 



Slides Loaned. — Mr. C. Baker, 244 High Holborn, Lon- 

 don, has opened a loan collection of microscopical slides to 

 general circulation. 



Micro-photography. — The difference betweenthe chem- 

 ical and visual foci must be found by experiment, and 

 marked down for future reference. The ground glass 

 ought to be replaced by a piece of plain glass, and a focus- 

 ing magnifier used ; a cheap one will answer perfectly. 



