66 THE AMERICAN MONTHLY [Apr. 



RECENT PUBLICATIONS. 



Bacteria. — Two books have just been published in Ger- 

 man on bacteria; one by Dr. W. Mig-ula and one by Dr. Al- 

 fred Fischer, the professor of botany in Leipzig-. The for- 

 mer is the first volume of a series, price 12 marks, and 

 contains a g-eneral survey of the classification, morpholog-y 

 and development of the schizomycetes. Six plates and ex- 

 haustive bibliographies are given. Dr. Fischer's book, price 

 4 m.arks, is upon non-pathogenic bacteria, and excludes 

 those met with in medicine. Metabolism, fermentation, 

 nitrification, and the various physical and industrial pro- 

 cesses get treated fully. There are chapters on morphol- 

 .ogy, classification, distribution, habitat, conditions of life, 

 nutrition, and culture, respiration with detailed account of 

 the relation of micro-organisms to nitrogens and carbonic 

 .acid. 



SCIENCE-GOSSIP. 



Faint Rays. — The ordinary leather and wooden walls of 

 a camera allow a certain amount of light to leak through 

 them, and the same is true of the imperfectly fitting slid- 

 ing joints of the microscopes. All such light which leaks 

 into the camera acts on the sensitive plate without helping 

 to produce the image desired and so as to blur that image. 

 But when the whole train of apparatus is within an actinic- 

 proof box the exposure can be made for hours or days, so 

 that the faint rays of the image can act cumulatively. This 

 makes it possible to expose a plate for a long time without 

 allowing any light to act on the sensitive plate except the 

 light which forms the image. — Gates. 



Yellow Fever. — The microbe of yellow fever is alleged 

 to be a fact. Dr. Sanarelli, director of hygiene of Monte- 

 video, who has demonstrated its existence and supplied a 

 remedy for the disease, will probably be entitled to the 

 150,000 scudi ($150,000) offered as a reward by the Brazil- 



