718 



SUMMARY OF CURRENT RESEARCHES RELATING TO 



droplets of saliva may be readily detected. (2) A series of speaking- 

 experiments was made in a small and also in a large room, first with the 

 artificial infection of the mouth with a living emulsion of B. prodigiosuSy. 

 and afterwards with no artificial infection, culture plates being placed 

 at different distances on the floor. By this means the presence in the 

 air of a room of invisible droplets of ordinary saliva emitted from the 

 mouth during the act of loud speaking was demonstrated at a distance 

 of 40 feet in front of the speaker, and at a distance of 10 feet behind 

 him. (3) The open air in several localities was examined both by 

 exposing broth plates for definite periods, and by aspirating the air 

 through a special apparatus. By these means twenty-two streptococci 

 were isolated from the open air, three of which resembled 8. brevis of 

 the saliva. Virulent anaerobic bacilli resembling B. enteritidis sporo- 

 (jenes were isolated five times, and micro-organisms of the B. coli type 

 thrice. 



Simple Method for Cultivating Anaerobic Bacteria.* — B. R. 

 Rickards recommends the following method (fig. 120) for solid media. 



A Agar. 



B Pyrogallol. 



C Broth. 



Fig. 120. 



Fig. 121. 



The tube of inoculated media is inverted into a tall vessel containing 

 a layer of dry pyrogallol, to which is then added a strong solution of 

 sodium hydroxide. As the oxygen is absorbed the solution rises in 

 the tubes. For liquid media the same procedure is followed, but a 

 tube is employed, the lower two inches of which is bent at an angle of 

 60°, and in this part is contained the liquid medium. For plate 

 cultures an inverted Erlenmeyer flask answers well (fig. 121). 



Sy mmers, W., St. C. — Method of maintaining the virulence of a pathogenic micro- 

 organism, Bacillus cholerae asiaticae. 



Centralbl. Bait, l*e Abt. Orig., xxxvii. (1904) pp. 23-4. 



* Centralbl. Bakt. Orig., xxxvi. (1004) pp. 557-9 (2 figs.). 



