138 









THE EVOLUTION OF LIFE 

proceed to charge them with 
measured amounts of liquor 
potassze. As in the previous 
experiments, the liquor po- 
tassz is delivered into a little 
porcelain pot; and the open 
capillary extremity of the 
glass tube, previously well 
heated in the fame “of = 
Bunsen’s burner, is immersed 
therein. When no more suit- 
able rest is at hand the little 
porcelain vessel may be placed 
in the angle between two 
bottles, so that the upper end 
of the heated tube inclines 
against them, partly for sup- 
port and partly that it may 
cool more quickly. In two 
or three minutes, when the 
whole of the liquor potasse 
has been forced into the tube, 
this is to be inverted, and its 
shoulder, where it begins to 
narrow (Fig. 4*), is heated in 
a spirit-lamp flame, so that 
the tube may be drawn out 
still more in this situation. 
- Subsequently the end of tube 
is bent, in the manner shown 
in the figure, and then her- 
A 
men 
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FIG. 3. 
Burette-tube for measuring metically sealed. 
liquor potassze. 
