110 SUMMARY OF CURRENT RESEARCHES RELATING TO 



(6) Miscellaneous. 

 CzAr ski, Siegfried— Grundziige der Theorie der optischen Instrumente nach. 

 Abbe. Second edition, edited by O. Eppeustein and M. von l!<ihr, 490 pp.. 17*> 

 tigs. J. A. Barth, Leipzig, 1904. 



Z e i s s, Cab i- — Die Bilderzeugung in optischen Instrument en, vom Standpunkte der 

 geometrischen Optik. By the Scientific Staff of Carl Zeiss's Works. Edited by 

 M. von Rohr, 55S pp., 133 figs. J. Springer, Berlin, 1904. 



B. Technique.* 

 (1) ^Collecting Objects, including 1 Culture Processes. 



Diagnostic Media for the Study of Bacteria.f — G. Marpman 

 describes the uses and methods of preparing various media for differ- 

 entiating bacteria according to the products formed by the growth of 

 the rganism. The production of acids or alkalies is indicated by 

 using lacmus gelatin or chalk gelatin ; reducing action is detected by 

 lacmus gelatin or " Rhodan-Eisen " gelatin ; sulphuretted hydrogen 

 by lead gelatin ; sulphur and sulphates by gelatin containing nitro- 

 prusside of sodium ; carbonic acid by chloride of calcium gelatin ; the 

 formation of aldehyde is demonstrated by " Malachit Sulfit " gelatin ; 

 the presence of agglutinins is shown by safranin gelatin ; and silver 

 gelatin, poured into specially devised yellow glass petri dishes, is used 

 to detect the formation of toxins, antitoxins, agglutinins, coagulins, etc. 



Detection of Bacillus Enteriditis Sporogenes in Water.! — E. T. 

 Hewlett recommends the following method. Into boiling tubes, 40 c.cm. 

 of milk are introduced ; the same are plugged and sterilised. At the 

 time of using, the tubes are boiled in a water-bath for a few minutes 

 to expel air, and 60 c.cm. of the water to be examined are added. The 

 wool plugs are now replaced by a cover of two thicknesses of sterile 

 filter-paper kept in place by a rubber band, and the tubes are then 

 heated at 80° C. for 10-15 minutes, and incubated anaerobically at 

 37° C. in a Bullock's apparatus, or in a stoppered museum jar of 

 suitable size containing alkalin pyrogallic solution. By using a dozen 

 tubes, 700 c.cm. of the water can thus be examined. 



Plate Culture of Anaerobic Bacteria. § — The apparatus described 

 by O. Berner consists of a flat vial with parallel faces, to one side of 

 which is fused a glass cock. The nutrient medium, to which has 

 been added some methylen-blue to indicate the absence of oxygen, is 

 poured into the vial, the neck of which is closed by a wool plug, and 

 the whole is boiled in a vessel of water until the bine colour begins to 

 disappear. The wool plug is now replaced by a perforated rubber 

 stopper, provided with a short glass tube and rubber tubing. Hydrogen 

 is then passed into the apparatus until the blue colour has entirely dis- 

 appeared ; the vial is taken out of the water, the neck now closed with 



* This subdivision contains (1) Collecting Objects, including Culture Pro- 

 cesses; (2) Preparing Objects; (3) Cutting, including Imbedding and Microtomes; 

 (4) Staining and Injecting ; (5) Mounting, including slides, preservative fluids, &c. ; 

 {(>) Miscellaneous. 



t Zeits.hr. angew. Mikr.. x. (1904) pp. 169-74. 



J Trans. Path. .Soc.,lv. (1904) p. 123. 



§ Centralbl. Bakt., l te Abt., xxxvii. (1904) pp. 478-S0 1 fig.). 



