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 bibliog-raphies are given. Dr. Fischer's book, price 

 4 marks, is upon non-pathog-enic bacteria, and excludes 

 those met with in medicine. Metabolism, fermentation, 

 nitrification, and the various physical and industrial pro- 

 cesses g-et treated fully. There are chapters on morphol- 

 og-y, classification, .distribution, habitat, conditions of life, 

 nutrition, and culture, respiration with detailed account of 

 the relation of micro-org-anisms to nitrog-ens and carbonic 

 acid. 



SCIENCE-GOSSIP. 



Faint Rays. — The ordinary leather and wooden walls of 

 a camera allow a certain amount of lig-ht to leak throug-h 

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

 ing- joints of the microscopes. All such lig-ht which leaks 

 into the camera acts on the sensitive plate without helping- 

 to produce the imag-e desired and so as to blur that imag-e. 

 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 imag-e can act cumulatively. This 

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

 allowing- any lig-ht to act on the sensitive plate except the 

 lig-ht which forms the imag-e. — Gates. 



Yellow Fever. — The microbe of yellow fever is alleg-ed 

 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- 



