itates, cold and dilute solutions produce light pre- 

 cipitates. 



How are soluble salts obtained in crystals? By 

 slowly evaporating the solvent from a saturated 

 solution. 



What other methods are used for obtaining crys- 

 tals? Sublimation and fusion. 



How is a crystal bounded? By plane surfaces 

 symmetrically arranged with reference to certain 

 imaginary lines passing through its centre, these 

 lines are called axes. 



What is the source and symbol of zinc? Found 

 in nature as sulphide (blende) or carbonate (cala- 

 mine) Symbol, Zn. 



What is the chemical and physical difference 

 between the red and yellow oxide of mercury? The 

 difference is only physical, the yellow being in a 

 more minute state of division than the red. 



Give numbers of the officinal powders and their 

 meaning. 



No. 20 Coarse. 



No. 40 Moderately coarse. 



No. 50 Moderately fine. 



No. 60 Fine. 



No. 80 Very fine. 



What is meant by an Impalpable Powder? One 

 which is reduced to the utmost fineness. 



What is the meaning of assay? 



To determine the quantity of a given substance in 

 a compound. 



Define analysis. 



Analysis is breaking up a compound and sepa- 

 rating its constituents. 



Define synthesis. 



Synthesis is the creation or preparation of com- 



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