936 



SCIENCE. 



[N. S. Vol. XV. No. 389. 



Against the wall of the laboratory (Fig. 

 6) is a long porcelain-lined sink, with five 

 taps, to which are attachable the tubes 

 leading to a still, an exhaust (with manom- 

 eter), and a blast, while the necessary 

 funnels, graduates, etc., are arranged above 

 and the pneumatic troughs, basins and the 

 like, beneath it. 



Of especial importance in such a green- 

 house are, however, two things, the tables 

 and the physiological dark room. There 

 are sixteen tables. Each top is of a single 

 thick, smooth slate, four feet by two, rest- 



sable in such a laboratory. Finally we con- 

 sider the physiological dark room, perhaps 

 the most essential part of the furnishing of 

 a laboratory of plant physiology. It is 

 built of one thickness of brick against the 

 wall of the laboratory (on the right in Fig. 

 6), but otherwise has an air space all 

 around it whereby it is kept approximately 

 at the average temperature of the green- 

 house. It is nearly six by six feet in area, 

 and from six to eight feet high inside. The 

 ventilation is provided for by an arrange- 

 ment of double-walled black boxes over 



Fig. 5. View in the Greenhouse, from the door of the Laboratory. 



ing at the four corners upon adjusting 

 screws by which they may be set level. 

 The stand, especially designed for the pur- 

 pose, is of cast iron, of such a pattern as 

 to give the greatest possible rigidity, and of 

 such a height as to bring the top of the 

 table three feet from the floor, a height 

 which experience has sho'wn to be the best 

 for the average student when working stand- 

 ing. They are proving perfectly satisfac- 

 tory in use. The central table of the green- 

 house is covered by a white wooden shelter, 

 lightly built, under which are kept the 

 autographic meteorological instruments, 

 thermograph, hygrograph, etc., indispen- 



openings left in the brickwork near the 

 floor, and by a triple roof with communi- 

 cating air spaces. The details cannot 

 readily be briefly described, but the re- 

 sult is a perfect system of ventilation with- 

 out the admission of the slightest ray of 

 light. The door has an inner porchway 

 with a second door, both made light-tight 

 by rubber strips, so that by closing one 

 door before opening the other, it is possible 

 to enter or leave the room without the ad- 

 mission of any light. It is provided vidth 

 shelves, and is entirely painted a dull black 

 inside. 



A point of much interest about this en- 



