APPARATUS AND METHODS. 



25 



pressure used being regulated by the thickness of the tube. Now 

 hold the tube in both hands, with the scratch away from the body 

 and the tips of the thumbs touching each other just opposite the 

 scratch. Break the tube by bending it, giving a pull at the same 

 time. Round off the sharp ends by fusing them in the Bunsen 

 flame hold the tube vertically until the flame is coloured strongly 

 yellow by the sodium of the glass. 



s 1 



BUCKLED 



u 



Fig. 17. 



Fig. 18. 



(d) Bend some pieces of Glass Tubing- to form Right 

 Angles. Use an ordinary spreading gas flame lowered until it is 

 about 2 in. across. Place the tube over the flame for a few seconds, 

 and gradually bring it down into the hottest part, as shown in 

 Fig. 17. Turn the tube round and round till it softens, then allow 

 one end to fall until it makes the required angle. 



The bend should be round and smooth ; the 

 Bunsen flame is apt to give buckled bends (Fig. 

 18). Do not remove the soot until the tube is 

 cool. 



(e) Bend some Tubing twice at Rig-lit 

 Angles so as to form Three Sides of a 

 Rectangle. When laid down all three sides 

 must touch the bench. 



(/) Make two Nozzles. Hold a piece of 

 tubing by both ends in a flame ; soften the 

 middle, and pull the ends slightly apart. Cut 

 the tube through and round off the ends. 



(g) Complete the Wash-bottle. Bend suit- 

 able pieces of tubing to form angles equal to 

 those seen in the wash-bottle in Fig. 19. Push Fig- 19- 



them through the cork prepared in (6), and at- 

 tach a nozzle by means of an inch or so of rubber tube. 



25. Experiments. In making experiments, sketch 

 the apparatus used. Make notes of the materials experi- 

 mented with (name of plant or part of plant, number, 

 condition, stage of growth, etc.) ; the duration of the 



