26 



after percolating or in separating fixed oils. The ordinary tinc- 

 ture or fruit press may be taken as an example. 



CoLATiON, or straining. This is the process of separating 

 solid, coarse particles from a liquid by pouring through a cloth or 

 strainer. 



Filtration is the process of separating fine or course, solid 

 particles from a liquid by pouring it through a finely porous ma- 

 terial, such as a filter paper. 



Decantation. — This means simply carefully pouring off most 

 of the liquid portion, leaving the rest in the vessel. By repeating 

 the process several times and adding more solvent each time, prac- 

 tically all the soluble material may be removed from the precipitate. 



Clarification. — This is the process of rendering turbid ma- 

 terials clear and transparent by removing the suspended solid 

 bodies. Often when the solid particles cannot be removed by the 

 filter, they may be removed by agitating them with some insoluble 

 powder, or by adding egg albumen, shredded filter paper and by 

 boiling or by centrifuge. 



Chapter VII. 



DISPENSING 



In dispensing medicines, every attention should be given to 

 have the package neat and attractive. While any bottle or paper 

 will serve in an emergency, we should so far as possible provide 

 good, clean,unlabeled bottles, not old beer bottles, whiskey flasks, 

 or patent medicine bottles, and dispense them wrapped in clean, 

 new paper. Powders should always be placed in uniform paper 

 and folded evenly, then wrapped in a neat package, or better still, 

 dispensed in boxes of suitable size. These in turn should be neatly 

 wrapped. 



Powders-Chartae. — These are preparations of solid drugs in 

 a fine state of division for external or internal use. Usually they 

 are combinations of two or more drugs, and frequently one of the 

 drugs only serves as a diluent or base. The drugs are usually 

 mixed by triturating with a mortar and pestle although there are 

 machines for tliis purpose, In mixing the materials, care should 



