494 SUMMAKY OF CURRENT RESEARCHES RELATING TO 



limb being a capillary tube, with a small bulb (0'25 c.cm. capacity) in 

 its upper part about 3 in. from the top of the tube. The short portion 

 of the long limb above the bulb may be calibrated, and the long 

 portion below the bulb should have an external diameter of about £ in. 

 0-25 c.cm. of the sugar medium is drawn up by teat-suction, followed by 

 10 c.mm. of a 24-hour culture of the gas-producing organism. The mixed 

 fluid is so arranged that it occupies the glass bulb, its proximal end 

 coming to lie at the commencement of the long portion of the capillary 

 tube. The end of the pipette is then sealed, and the apparatus is placed 

 in the incubator in the vertical position. As gas is formed during 

 incubation, so the column of fluid is displaced downwards, and by careful 

 marking of the level of the fluid at different times, the volume of gas 

 evolved can be calculated. 



Inset Absorption Appliance for the Test-tube Culture of An- 

 aerobes.*— R. M. Buchanan has devised an inset absorption appliance 

 for the test-tube culture of anaerobes which obviates many of the dis- 

 advantages incidental to the ordinary use of pyrogallic acid and potassium 

 hydroxide for this purpose. The device consists of a short inset tube 

 (30 by 13 mm.), with the lower end sealed round a shorter and narrower 

 tubule (20 by 3 mm.), which extends upwards in the centre as a vent. 

 The upper end is fitted with a rubber stopper, which also suspends the 

 inset tube in the tube containing the nutrient medium, and hermetically 

 closes the latter tube. The approximate quantities of pyrogallic acid 

 and potassium hydroxide to be used with this apparatus have been worked 

 out as 0-25 c.cm. of a 40 p.c. solution of each reagent for every 10 c.cm. 

 air space. The pyrogallic acid may also be used in tabloid form, which 

 allows more time for manipulation. The method is equally effective for 

 liquid or solid media. 



Disinfectant Action of certain Bacterial Stains.f— A. M. Jansen 

 has conducted an investigation into the question of the viability of 

 bacteria under the action of some of the commoner laboratory stains. 

 Aqueous solutions of methylen-blue or fuchsin have little or no bac- 

 tericidal action, even in dilutions as low as 1 : 200. Aqueous solutions 

 of gentian or crystal-violet (1 : 10,000 for 30 inin.), on the other' hand, 

 show a marked disinfectant action on staphylococci but not on Bacillus 

 coli. With regard to the action of staining reagents made up for 

 laboratory use, it is concluded that organisms in slide preparations 

 which have escaped destruction by drying and fixing, are not safe to 

 handle when stained with methylen-blue, but are innocuous when stained 

 with anilin-gentian-violet, Gram's stain, or strong carbol-fuchsin. 



Use of Glucose-Nasgar for Restoring lost Pigment-producing 

 Properties.} — E. Emrys-Roberts has demonstrated the fact that stock 

 cultures of Bacillus prodiyiosus and B pyocycmeus which have lost their 



* Centralbl. Bakt., lte Abt., lxxiv. (1914) pp. 526-7 (1 fig.), 

 t Journ. Infect. Diseases, xiv. (1914) pp. 255-60. 

 % Journ. Path, and Bact., xix. (1914) p. 127. 



