116 SUMMARY OF CURRENT RESEARCHES RELATING TO 



Bacteriological Methods in Sanitary Water Analysis.* — C. E. 

 A. Winslow and C. P. Nibecker in an extensive series of water examina- 

 tions employed the following bacteriological methods : (1) The gelatine 

 plate at 20° C, the count being made after 48 hours. This count was 

 found to roughly correspond to the free ammonia and " oxygen con- 

 sumed" of chemical analysis, and indicates the amount of organic 

 decomposition in process. A low count is, of course, highly reassuring, 

 but a high one may only mean an exceptional multiplication of certain 

 water forms. (2) The fermentation test, as determined by the gas 

 formula obtained in dextrose-broth tubes after 24 hours, at 37° C. 

 This was found to be especially useful as an indicator of B. coli. 

 (3) The litmus-lactose-agar plate after 24 hours, at 37° C. This, by 

 means of the total count and the count of the red colonies, gave a 

 measure of the organisms which thrive at the body temperature, and 

 of those which form acids, which latter are coming to be recognised as 

 intestinal forms. 



Technique of the Bacteriology of the Blood.f — R. C. Rosenberger 

 quotes the following procedure adopted by Coplin, who has elaborated 

 and extended Sittmann's method. The middle half of the arm is washed 

 with hot soap and water, and then with sterile water and GO p.c. alcohol. 

 The arm is then covered with 1 to 1000 sublimate gauze. In 24 hours it 

 is cleaned with alcohol and ether, followed by hot 1 to 1000 perchloride, 

 and lastly with sterile water or normal salt solution. All the solutions 

 should be used hot. The blood is withdrawn from the median vein 

 with a syringe or an aspirating needle. 20 c.cm. of blood should be 

 obtained. From this, plates maybe made bypassing blood into liquefied 

 agar kept at 45° C, in the proportion of 2 to 3 c.cm. of blood to 6 c.cm. 

 of medium. After thorough mixing, plates are made and incubated at 

 37° C. Bouillon in flasks should be inoculated ; 8 to 10 c.cm. of blood 

 should be divided among flasks each containing 150 c.cm., so that the 

 dilution is from 1 to 75 to 1 to 150. The flasks are well shaken and in- 

 cubated at 37*5. If the bouillon become cloudy it is plated upon agar. 

 Agar and serum slopes should be inoculated with 1 to 2 c.cm. of blood. 

 Spreads on slides should be made, and animals inoculated with at least 

 5 c.cm. of blood. A sample of the blood may be incubated as a control 

 or enrichment. Special solid media should be used for certain kinds, 

 as urine agar or blood-serum agar for gonococcus, blood-smeared agar 

 for Bacillus influenzal. The spreads and films should be stained with 

 anilin pigments. The haemoglobin may be removed by immersion in 

 5 p.c. acetic acid for ten seconds. The acetic acid is removed by rapid 

 aeration and by exposure to ammonia vapour. The film may then be 

 stained for bacteria, the removal of the haemoglobin facilitating the 

 search for micro-organisms. 



Cultivating Trypanosomes.t— W. J. McNeal and F. G-. Novy have 

 cultivated Trypanosoma lewisi in a mixture of defibrinated rabbit's blood 

 and agar. Agar, prepared in the usual way, is sterilised and cooled 



* Technology Quarterly, xvi. No. 3 (1903) pp. 227-30. 

 t Araer. Juuru. Med. Sci., exxvi. (190b) pp. 234-57. 

 % Bull. Inst. Pasteur, i. (1903) p. 602. 



