and Laboratory Methods. 2409 



Note on a Method of Preparing Sugar-Free Bouillon. 



The method herein described has probably occurred to others, but not hav- 

 ing seen it mentioned anywhere, I have taken this opportunity to present it, 

 hoping that it may be of value to some of those who work a great deal with this 

 medium. 



The original method by which this bouillon was prepared, that of allowing 

 the beef-infusion to undergo putrefaction, and at the same time fermentation, and 

 the method which followed this, that of fermenting the already contaminated 

 (ordinary putrefaction organisms) beef-broth with the Bacillus coli communis, 

 are open to the objection that the putrefactive organisms (especially the Proteus 

 vulgaris) present in the meat produce a very foetid odor, which makes the pre- 

 paration and handling (the odor remains even after the medium has been boiled 

 and sterilized) of this medium extremely disagreeable. 



I found that, if the infusion was sterilized previous to the inoculation with 

 the Colon bacillus, a perfectly odorless and sugar-free broth could be obtained. 

 The method in detail is as follows : To a portion of the round of beef 

 (lean), ground fine, add double its weight of cold water and bring slowly to a 

 temperature of 50° C. over water bath. Maintain at this temperature for three 

 hours, then strain broth through muslin. Put meat infusion thus obtained into 

 sterile flasks and sterilize for three-quarters of an hour in live steam. After 

 sterilization allow to stand in ice-box over night and then inoculate with a pure 

 culture of the Bacillus coli communis. Cultivate from eighteen to twenty-four 

 hours at 37.5° C. and then boil and filter to get rid of the extraneous meat par- 

 ticles. Now add ^ per cent, of NaCl and ^ per cent, of peptone and boil for 

 three-quarters of an hour. Neutralize with NaOH, filter, put into sterile flasks 

 and sterilize. 



The medium thus obtained is odorless and completely sugar-free and may be 

 used for the demonstration of the indol reaction or as a basis for the fermenta- 

 tion media (made by adding to it 1 per cent, of glucose, lactose or saccharose). 

 Bio-chemic Laboratory, Bureau Animal Industry. F. E. MONTGOMERY. 



A Method for Staining Polar and Other Granules in 



Bacteria. 



This stain was devised by J. F. Broderick, a member of the laboratory corps. 



Broderick's Method. — Prepare a smear in the ordinary way on a slide. Add 

 Loeffler's methylene blue, sufficient to cover the preparation yL inch deep. Add 

 pure undiluted hydrochloric acid, 1 to 3 drops, and tilt back and forth to mix 

 with the methylene blue until an irridescent film forms on the surface of the 

 methylene blue. Drain and add 3 drops of carbol fuchsin ; tilt to mix : drain ; 

 add more fuchsin ; tilt and mix until stain becomes a deep reddish-purple color, 

 then drain and wash. The smear should be a light pink. The granules are 

 deep red, blue red, or black, the rest of the cell faint red or pink. 



