152 COLLEGE BOTANY 



A solid is also composed of particles, but is mucli less mobile 

 than a liquid, and it retains its form more or less perfectly. 

 Some solids are soluble in liquids and some are soluble in other 

 solids. Some may be liquefied and then vaporized. 



Solution. — All gases, liquids and solids are made up of par- 

 ticles, and when the particles of two are brought in contact they 

 usually tend to intermingle to a greater or less degree ; i.e., one 

 is dissolved by the other. Gases are very generally dissolved in 

 liquids, the liquid being the solvent and the gas the solute. Many 

 solids are dissolved in liquids; the liquid being the solvent and 

 the solid the solute. Some liquids are dissolved in others ; e.g., 

 glycerine in water, the water being the solvent and the glycerine 

 the solute. Some liquids, such as oil and water, will not inter- 

 mingle. In some cases a solid is dissolved in a measure by 

 another solid, but the process is always very slow ; e.g., the par- 

 ticles of lead and gold, if kept in contact for a long period of 

 time, will intermingle very slowly. 



