12 COMPANION TO TROPICAL READERS 



12. Take a pride in your notebooks, your collections, 

 your experiments, and your school garden. 



THE USE OF APPARATUS 



In order that all the practical experiments outlined 

 in this Companion should be satisfactorily carried out, 

 teachers will have to make use of some chemical appa- 

 ratus and of some reagents. It will often be found that 

 interesting experiments can be successfully performed 

 with simple appliances and with chemical substances in 

 common use, and it is indeed preferable to make use 

 of familiar articles whenever possible. 



Any experiment that the teacher proposes to do for 

 the benefit of his class should be tried beforehand. This 

 is important, and will safeguard against annoyance of 

 the teacher and disappointment of the scholars. It has 

 been said of the famous chemist Faraday that in pre- 

 paring for his lectures he always tried the stoppers of 

 the bottles he intended to use, in order to make sure 

 that they could easily be taken out. 



Teachers often extend their work in chemistry beyond 

 the limits of the experiments suggested by the text 

 matter of the Tropical Headers, and the notes given 

 here will, it is hoped, enable them to do such further 

 demonstrations as they may desire. 



The necessary manipulation will be found quite easy. 

 The following notes are intended for those teachers who 

 have had no training in practical chemistry: 



Folding Filter Paper. The paper should be first 

 folded in half and the centre creased; this should 

 then be doubled over again (as shown in fig. 2), and 

 opened out so that a funnel is formed with three folds 

 of paper on one side and one on the other. 



