366 SUMMARY OF CURRENT RESEARCHES RELATING TO 



B. Technique.* 

 CD Collecting- Objects, including: Culture Processes. 



Anaerobic Plate Cultures.f — H. S. Fremlin describes a simple- 

 apparatus for anaerobic plate cultures. It consists of a circular glass, 

 chamber 5 in. in diameter and 1 in. in depth — sufficiently large to take- 

 the ordinary 11 cm. Petri dish — provided with a wide carefully ground 

 rim. The lid of the chamber is flat and ground at the periphery where - 

 it comes into contact with the rim of the chamber. The ground surfaces 

 which come into contact are well smeared with vaseline to secure perfect 

 sealing of the chamber. The inoculated plate resting in the lid of the 

 second Petri dish is placed in the chamber, and pyrogallic acid and caustic- 

 soda solutions are then introduced, as is done in preparing a Buchner's 

 tube anaerobic culture, and the lid secured in position. Chemical and 

 bacteriological tests prove the efficiency of the apparatus. 



Ring Test for Indol.J — S. B. Grubbs and E. Francis, in utilising the 

 acid nitroso-indol reaction, suggest the employment of the test under 

 certain standard conditions, viz. applying the test to cultivations in fluid 

 media containing 1 p.c. peptone, and grown for 24 hours at 87° C, in the - 

 following manner. About 8 to 10 drops of pure concentrated sulphuric 

 acid are added to 7 c.cm. of the cultivation in a test-tube and the mixture 

 well shaken. Three or four cubic centimetres of a 1 in 1000 sodium 

 nitrite solution are carefully run down the side of the tube so as to form 

 a layer on the surface of the mixture of culture and acid. In the 

 presence of indol a pink ring at the junction of the two fluids should 

 show up sharply and distinctly within a period of one hour — the time 

 limit allowed for contact. 



Differentiation of True and False Diphtheria Bacilli.§ — J. Bronstein 

 and E. N. Griinblatt, relying on the fact that the Klebs-Loeffler bacillus 

 produces acid quite early in the course of its growth whilst the pseudo-- 

 diphtheria bacillus produces alkali, propose to differentiate these two 

 organisms by testing cultivations with Minkowski's reagent. This* 

 reagent is prepared by adding a mixture of 2 parts of a 2 p.c. watery 

 solution of indigo-carmin and 1 part of a 10 p.c. solution of acid 

 fuchsin in 1 per cent, caustic soda solution to 22 parts of dis- 

 tilled water. The reagent gives a ruby red colour in the presence of ' 

 acid, and green in that of alkali. Cultures are made in pepton-broth 

 with half per cent, glucose (titrated at incubation temperature with 

 Minkowski's reagent as the indicator and rendered exactly neutral), and 

 are incubated at the body temperature for twenty-four hours, together 

 with uninoculated control tubes. At the end of this time about H drops 

 of Minkowski's reagent are added to each tube with the result that the 



* 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. ;: 

 (ti) Miscellaneous. t Lancet, 1903, i. p. 518. 



X Bull. 7, Hygienic Lab. U.S. Marine Hospital Service, 1902. 



§ Centralbl. IJakt, 1" Abt. Orig., xxxii. (1902) pp. 425-8. 



