ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 231 



Magnesium Phosphate in the Preparation of Media.* — A. Cache 

 recommends the following method for the preparation of bouillon. Take 

 250 grm. of meat, 500 grm. of water, and 1 grm. of MgNH 4 P0 4 , and allow 

 the mixture to stand in a flask for 24 hours in the cold. On filtering, 500 

 grm. of meat extract are obtained, the alkaline reaction of which is then 

 estimated. Add 1 p.c. of pepton and 0*5 p.c. of NaCl, thoroughly shake 

 the mixture, and place in autoclave for 2 minutes at 120° C. After 

 filtering, when cool, there is obtained a clear fluid slightly alkaline to 

 litmus. In this medium the author finds that micro-organisms develop 

 better and retain their virulence longer than in media prepared after the 

 usual method. 



Early Diagnosis of Typhoid Fever .f — H. Conradi has devised a 

 method by which a diagnosis of the presence of Bacillus typhosus in the 

 blood can be demonstrated in not more than 32 hours. It is based on 

 the observation that the blood in vivo is less bactericidal than in vitro, 

 under which latter condition substances are developed which exert a 

 disinfectant action as a result of coagulation. Coagulation is prevented 

 by the use of bile, the important components of which in respect of this 

 action are due to glycocholate and taurocholate of sodium. The medium 

 ■consists of bile, 10 p.c. pepton, and 10 p.c. glycerin. The blood is 

 obtained by pricking the ear, and allowing it to pass into a capillary 

 pipette containing a small quantity of bile fluid. From the capillary 

 pipette the mixture is transferred to a small glass tube containing 

 2-3 c.cm. of the pepton-glycerin-bile medium. The process of transfer- 

 ence is continued until the ear ceases to bleed. The proportion of 

 blood used must be as 1 to 3 of the medium. The tube is incubated at 

 37° C. for 10-16 hours, and cultures are then made on the Drigalski- 

 Conradi agar plates. J 



New Method of Differentiating Bacillus typhosus and Bacillus 

 coli.§ — L. S. Dudgeon read a preliminary communication before the 

 Pathological Society on the use of urotropin medium as a means of 

 diagnosis between B. typhosus and B. coli. From a series of experiments 

 he found that the most suitable strengths of urotropin were ■ 1 p.c, 

 • 5 p.c, and 1 ■ p.c, more especially in a broth medium. He had 

 also employed the same strengths of urotropin in agar, both for slants 

 and for plating. He had experimented with cultures of B. typhosus 

 obtained from two cases of bone abscesses, and stock cultures isolated 

 from the spleen in cases of typhoid fever. The results were constant. 

 B. typhosus grew well in 0*1 p.c. urotropin broth, fairly well in 0*5 p.c, 

 but the growth was delayed ; 1 p.c. urotropin broth was always sterile, 

 whereas B. coli obtained from cases of peritonitis and cystitis gave an 

 abundant growth in 0*1 p.c. and 0*5 p.c, and a fair growth in 1 p.c 

 If a tube of 1 p.c. urotropin broth were inoculated with the typhoid 

 bacillus and incubated at 37° C. for 24 hours, and then considerably 

 diluted (twice and three times), and then reincubated, no growth resulted 

 in any case. A paratyphoid bacillus (Krai) was found to grow well on 



* Centralbl. Bakt., Orig., lte Abt., xl. (1905) p. 255. 



f Deutsche. Med. Wochenschr., Jan. 1906. See also Brit. Med. Journ., 1906, i. 

 j p. 339-40. \ See this Journal, 1902, p. 371 ; 1904, p. 369 ; 1905, p. 259. 



§ Brit. Med. Journ., 1906, i. pp. 143-4. 



