ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 



235 



Reaction of Mammalian and Avian Tubercle Broth Cultures. — 

 0. Bang by growing cultures in very small amounts of medium, and 

 also by employing flasks whereby the lower strata of the media could be 

 readily examined, was able to show by the reaction curves that the sub- 

 strata of the broth in the cultures of 

 bovine and also of avian tubercle 

 became more alkaline, whereas the 

 similar curves of human tubercle culture 

 reaction showed, after an initial fall 

 towards or below the neutral point, an 

 increased acidity. The author found 

 that the reaction curves depended on 

 the amount of the medium in the 

 culture flask, on the age of the culture, 

 and on the original reaction of the 

 medium. 



Positwn normaLef 

 Acs tubes 



© (3) 



o 



Collecting 



Sea-water for 



Bacte- 

 riological Study.t — P. Portier and J. 

 Richard describe an apparatus which con- 

 sists of a cylindrical glass vessel A, 86 cm. 

 long and 16 mm. in diameter (lig. 48), 

 the wall being sufficiently thick to resist 

 a pressure of at least 600 atmospheres. 

 The vessel ends below in a short capil- 

 lary tube a b, and above in a long 

 capillary tube c d, e f, g h, with three 

 bends. A drop of water is introdiiced 

 into the ampoule A ; tlie end a is then 

 closed in the flame, and the long capil- 

 lary tube connected with a mercury 

 pump to exhaust the air. AVhen a 

 vacuum is obtained, the tube is closed 

 at A. The exhausted tube is then steri- 

 lised at 120°. This done, it is inserted 

 in a metal box, being fixed with copper 

 wire in such a way that the point /; h 

 projects from the upper end of the box. 

 The ai3paratus is then attached to the 

 plummet line, and let down to the de- 

 sired depth. By means of a messenger 

 sent down on the plummet line, the box 

 is set free from the collar, it turns over, 

 and the projecting tube strikes an iron 

 bar, whereby it is broken at the con- 

 striction </. The apparatus then fills with 



sea-water. It is then drawn up, and as it nears the surface it 

 warmer ; in consequence, a fine stream issues from g, and this 



* Centralbl. Bakt., Ite Abt. Orig., xliii. (1907) p. 34. 

 t ComiJtes Rendus, cxlii. (190G) pp. 1109-1111 (4 figs.). 



Fig. 43. 



Fig. 44. 



becomes 

 serves to- 



