340 SUMMARY OF CURRENT RESEARCHES RELATING TO 



the other, a stouter similarly flagellated form to which is given the 

 B. metarabinwn. This bacterium is the producer of the insoluble 

 (metarabin) gums as the other is of the soluble (arabin) gums. 



Colourless Bacterium obtaining Carbon from the Air.* — Beijerinck 

 and van Delden, in a very important paper, describe a new bacillus 

 B. cligocarbopltilus, which is able to grow in solutions containing only 

 mineral salts. The carbon necessary for its growth is obtained from the 

 air, not from the carbon dioxide, but from a complicated carbon-com- 

 pound (or compounds) present in the air in small quantities, the exact 

 nature of which is not clearly understood. The existence of a complex 

 carbon-compound in the air was first suggested by Karsten in 1802 ; of 

 late years this body has been investigated by Henriet, who believes that 

 it also contains nitrogen. The bacillus is widely distributed in the soil, 

 and can easily be obtained by infecting with garden-earth ordinary 

 nutritive salt-solutions (such as are used by botanists for water-cultures), 

 but made alkaline with K 2 HP0 4 instead of acid with KH. 2 P0 4 . The 

 bacteria soon form a thin, snow-white, dry layer upon the surface of 

 the fluid. The nitrogen can be supplied either in the form of potassium 

 nitrite, or an inorganic ammonium salt. No use can be made either of 

 the free carbon dioxide of the air or of that contained in carbonates in 

 solution. The presence of organic carbon-compounds is inimical to its. 

 growth, but, like the nitrifying bacteria it can be grown under suitable 

 conditions on agar and silicic acid (water-glass). 



Bacterial Flora of the Nose.f — Hasslauer has investigated the 

 bacterial flora of the mucous membrane of the nose of man in health and 

 disease. Eighty-four persons of various occupations was examined, and 

 in nearly all cases a large number of bacteria was met with both in the 

 healthy and diseased cases, but in no case was the tubercle bacillus 

 found. 



Cultivation of Anaerobic Bacteria. f-i-A. Weichselbaum gives a 

 short introduction on the gaps in our knowledge of anaerobes, and his 

 assistants, Dr. Anton Gohn and Dr. Milan Sachs give a detailed account 

 of the technique employed in studying these forms. 



Biology of Anaerobic BacteriaJ — Karl Koninski has made a series 

 of observations on the cultural characters in parallel series of gangrene 

 and oedema bacillus. In some of the experiments these two anaerobes 

 after being infected on the surface of gelatin, where they naturally 

 remained sterile, were made to grow by a later infection with the aerobic 

 Micrococcus candicans. 



Effect of Oil on Bacteria. |] — Dr. Kurpjuweit has investigated the 

 capacity of bacteria to live in oil, especially in relation to the use of oil 

 for lubricating catheters. Ordinary olive oil was investigated and 

 found to contain bacteria but not pathogenic forms. The effect of olive- 

 oil upon various pathogenic bacteria was also investigated and it was 

 found that they remained living for some time, up to 10 days, in the oil ; 



* Centralbl. Bakt., x. (1903) pp. 33-47. 



t Op. cit., xxxiii. (1903> pp. 47-51. t Op. cit , xxxii. (1902) pp. 401-13. 



§ Tom. cit., pp. 569-73. || Op. cit. xxxiii. pp. 157-60. 



