FIG. 28. Folding filter 

 paper for a funnel. 



the contents of the beaker into the 

 funnel, catching in a glass the liquid 

 which runs through the funnel (Fig. FIG. 29. -Filtration. 

 29). The solid precipitate stays be- 

 hind. The liquid filters through, and the action is called 

 filtration. What use is made of filtration in the home"? 



EXPERIMENT 28. SOLVENT ACTION OF WATER 



Put some clean bright pieces of lead in a beaker con- 

 taining water and allow the beaker to stand for a day or 

 longer. Then pour off the clear water into another beaker 

 and add a few drops of hydrochloric acid and a slight 

 amount of hydrogen sulphide water. If the mixture of 

 water, hydrochloric acid, and hydrogen sulphide turns 

 black or brown, it indicates that lead is present in the 

 water. Lead is poisonous and produces illness if it is 

 taken into the system constantly, even in small quantities, 

 and water containing lead in solution is very dangerous. 



