642 SUMMARY OF CURRENT RESEARCHES RELATING TO 



burners placed underneath, the beat being radiated from a metal plate 

 at the bottom and one at the top, and the metal tubes connecting them. 

 The tubes are arranged at the sides and back, and are placed close to 

 one another. The drawers are made of sheet zinc with a wooden front. 



Fig. 174. 



Each is 49 cm. long, 10*5 cm. wide, and 19 cm. deep. The sides and 

 back are perforated. The drawers are provided at the top with a narrow 

 flange which runs in a metal groove, and in which the drawers are sup- 

 ported. In front of each drawer are a pull and a frame for a card. 

 The Roux bimetallic regulator is inserted at the back. 



Improved Cultivation Capsules.* — Dr. E. J. Petri describes some 

 improvements and modifications of his well-known culture dishes. The 

 covers are now made of yellowish-brown glass in order that the growth 

 of the colonies should not be interfered with by the harmful action of 

 the red and violet rays. The dishes and covers, which are circular as 

 of yore, are of two patterns. In fig. 175 the dish has upright sides ; the 

 flange of the top-piece is twice as thick as the rest of the cover, and its 

 upper edge projects above the general level in order to prevent slipping 

 of the dish above. In fig. 176 the side of the dish is sloped outwards, 

 while the margin of the cover is bent to an acute angle into which the 

 side of the dish is received. At *, figs. 175 and 176, is shown a plate 

 made of yellowish-brown glass, having a circular rim within which the 

 lowermost dish is inserted. This serves to make a pile of dishes quite 



* Centralbl. Bakt. u. Par., l te Abt., xxviii. (1900) pp. 79-82 (6 figs.). 



