ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 
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action, and is easily made by cutting off the bottom of a test-tube and 
plugging an end with a caoutchouc stopper perforated in two places (for 
the long arm of the siphon and for the inflow tube). The long arm is 
about 14 cm. long, and the short one varies from 1 • 5-3 • 5 cm. according to 
the quantity required to be drawn off. The inflow has a small opening 
at the side, and in order to avoid bubbling is only pushed in so far that 
the fluid pours out at the lowest level. To the free end of the inflow 
pipe a rubber tube which can be clamped, may be attached and to this a 
glass tube to be immersed in the nutrient medium. By squeezing the 
air out of the rubber tube, the inflow current is started, and may be 
regulated by the clamp. In order to facilitate ready working and com- 
plete evacuation, the short arm of the siphon is expanded into a funnel- 
shape, and the funnel must be so wide as to allow the outflow quantity 
time to escape before the inflow reaches the mouth of the siphon. 
Simple Thermostat applicable to any Microscope." — Mr. G. H. F. 
Nuttall has devised a very simple thermostat, which can be adapted to 
any form of Microscope. The illustrations show the apparatus open and 
closed ; it is made of copper, and has the following dimensions : — 
breadth 16 cm., length 18 cm., height in front 20 cm., behind 13 cm. 
* Centralbl. f. Bakteriol. u. Parasitenk., l te Abt.,xviii. (1895) pp. 330-2 (2 figs.). 
