ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 659 



every guinea-pig weighing 250 grin, in the course of 4 days, or at the 

 very latest, 5 days. 



For the preparation of the toxin he uses a culture of " Park's 

 "bacillus No. 8 " grown as a surface growth in a special bouillon ; the 

 strongest poisons being obtained when the surface growth is heavy and 

 the broth remains clear. The medium known as " Smith's bouillon " is 

 prepared as follows : the meat is ground in the usual way, the expressed 

 juice being collected, weighed and added to twice its weight of water, 

 placed in the cool for 24 hours, strained, and again weighed ; it is then 

 neutralised with sodium hydrate to 1*5 p.c. acidity to phenolphthalein ; 

 it is now inoculated with B. coli communis, by adding 10 c.cm. of a 24- 

 hour old broth culture for each litre of the meat infusion ; this is grown 

 at 37° C. for 24 hours ; add the white of one egg for each litre of the 

 infusion, heat for 20 minutes to coagulate the albumen, and filter while 

 hot through paper ; weigh the filtrate obtained, and add water to make 

 up the loss ; neutralise with sodium nitrate to an acidity of • 5 p.c, 

 add 1 p.c. pepton, | p.c. sodium chloride, and ■ 1 p.c. dextrose ; heat 

 again for 20 minutes in streaming steam in an open autoclave ; again 

 neutralise to • 5 p.c, filter through paper and fill into Fernbach flasks, 

 then sterilise in the autoclave at 120° C. for 20 minutes. The flasks 

 are then inoculated on the surface from a 24-hour old culture, and 

 incubated for 7 days at 37 "5° C. The bouillon is then passed through a 

 porcelain filter by means of a vacuum, and stored in flasks provided 

 with a syphon and Maasen nozzle for the convenience of drawing off small 

 amounts from time to time. The toxicity of the poison is then determined 

 by inoculating guinea-pigs. The writer describes the usual method 

 of preparing antitoxic serum, and indicates the precautions to be taken 

 in order to keep the serum dry and free from the oxidising action of the 

 air, by the influence of phosphoric anhydride, and by storing it in a 

 special ice-box at 5° C, and so guarding it against the action of light 

 and maintaining it at a constant low temperature. For determining the 

 antitoxic value of this serum, a glycerinated solution is made by weigh- 

 ing 1 grm. of dry serum and dissolving it in 1 part physiological salt 

 solution (0*85) and two parts glycerin. From this solution, by means 

 of specially made pipettes, varying dilutions with physiological salt 

 solution are obtained. Exact amounts of the dilutions of toxin and of 

 serum are now filled into specially prepared syringes, where they are 

 actively shaken to obtain an intimate mixture and are placed at room 

 temperature in diffused light one hour before inoculation into the guinea- 

 pigs. The animals always receive a total of 4 c.cm. of fluid, injected 

 subcutaneously in the median abdominal line. As the limit of the 

 minimal lethal dose or the mixture containing the L + dose of the 

 toxin and one immunity unit is approached, one of three results occurs : 

 (a) the animal dies from acute poisoning on about the fourth day ; (b) 

 it develops post-diphtheric paralysis between the fourteenth and thirtieth 

 day ; (c) it recovers. 



Method for Growing Anaerobic Organisms under Aerobic Con- 

 ditions.* — CI. Tarozzi has devised a medium on which he has succeeded 



* Ceutralbl. Bakt., l te Abt xxxviii. (1905) p. 619. 



