334 



SUMMARY OF CURRENT RESEARCHES RELATING TO 



inoculated on a calf, which ahout the tenth day exhibited the charac- 

 teristic pustules. 



Medium for Bacteriological Examination of Water.* — Dr. P. 

 Miiller finds that far more species of water bacteria develope on albumose- 

 agar (Heyden's Nahrstoff) than on ordinary alkaline nutrient bouillon, 

 and that the difference in the number of germs developed in the two 

 media is greater when the water is less impure than in waters much 

 contaminated. 



(2) Preparing- Objects. 



Permanent Preparations of Bacterial Cultures.f — Dr. Th. Paul 



makes permanent preparations of cultures in Petri dishes after the 

 following manner : — The cover of the culture-dish is grooved so as to 

 fit accurately into the upper edge of the dish. The cultures are killed 

 with pure formalin. A circular piece of filter paper soaked in formalin 

 is placed over the dish and the lid put on, after which the whole is 



placed in a tin box. A vessel filled 

 with formalin is also placed inside 

 the box. In a few days the culture 

 is quite dead. The cover is then 

 fastened on. The groove is filled with 

 finely powdered white sealing-wax. 

 The lid is placed in a hot-air steriliser 

 to melt the wax. Meanwhile, the dish 

 is placed upside down on a hot metal 

 plate, so as to heat the edge of the 

 dish. When ready the dish is inserted 

 into the groove and pressed down. 

 When cold the cover and dish are 

 ] F firmly, united, and the apparatus is 



J HI 1 rendered perfectly air-tight. 



/ \ If a large number of preparations 



are required a special gas-stove is 

 advisable. 



Fig. 60. 



Cork 



Beaker 



Bougie 



Chimney 



... Beaker 



Flask 



for 

 Serum 



Method for obtaining Sterile 



Blood-Serum. :}: — 0. G. Schoneboom 



obtains sterile serum by filtering 



through a porcelain bougie without 



artificial pressure. One end of an 



ordinary lamp-chimney is plugged 



with a cork, which is perforated to 



admit the bougie, the lower end of 



the latter dipping into a flask or other 



suitable vessel (see fig. 60). The 



chimney is placed inside a beaker, 



and its upper end covered with another. Some dozen or so of these 



apparatus aro put up, and having been placed on a hot-air steriliser at 



160° for an hour, are allowed to cool in a quiet room or cellar. The 



* Arch.'f. Hygiene, xxxviii. (1000) pp. 350-66. 



t Centralbl. 13akt., 1" Abt., xxix. (1901) pp. 25-9 (3 figs.). 



t Tom. cit., pp. 210-1 (1 tig.). 



