OTHER SOLVENTS 97 



not to be near a fire, or even be in the same room with a 

 fire or a burning lamp,, for both are very easily set on fire. 

 Gasolene produces a gas which may be set on fire by a 

 flame although several feet away. 



Experiment 49. *The Use of Gasolene and Alcohol 

 as Solvents. 



Apparatus: Two small bottles with stoppers. 



Materials: Gasolene, alcohol, kerosene, pieces of 

 cloth, grease (lard), rosin,- pitch. 



a. Shake a little grease with water in a bottle. Does 

 the grease dissolve in the water? Pour off the water, add 

 gasolene and shake again. What is the result? 



b. Put a very little grease on a piece of cloth. This 

 will make a grease spot. To remove the grease spot the 

 space all around the spot should be wet with gasolene 

 before putting the gasolene upon the spot itself. If 

 gasolene is put upon the grease first the grease will 

 spread and leave a ring after the spot has been removed. 

 Try putting the gasolene upon a grease spot on a second 

 piece of cloth and notice the familiar ring when the 

 gasolene has evaporated. 



c. Shake ? Httle powdered rosin witb water in a bot- 

 tle. Does the water dissolve the rosin? Pour off the water, 

 add some alcohol, and shake again. What is the effect of 

 alcohol upon the rosin? Pour the result upon a smooth 

 piece of wood and allow the alcohol to evaporate undis- 

 turbed. How does the wood appear? Rosin is used in 

 cheap varnishes. Do the cheap varnishes scratch easily? 



d. Put some pitch upon a piece of cloth and remove 



* This experiment may be omitted or performed only by 

 the teacher. 



Elem. Sci. 7 



