

should make it the rule to send out preparations free from precipitate and 

 of an attractive colour. In some cases the incompatibility may be over- 

 come; for example the carbonates and the bicarbonates, the bromides and 

 iodides of the alkaloids while less soluble in water than the usual salts, are 

 comparatively soluble in alcohol, and hence the addition of alcohol will 

 prevent the precipitation. In other cases it may be possible by increasing 

 the viscosity of the mixture by the addition of acacia, tragacanth or syrup 

 to prevent the formation of a precipitate or much more often the addition of 

 one of these ingredients will so prevent the clotting of the precipitate that 

 it may be safely dispensed with a "Shake the Bottle" label. 



There are some substances such as, the salts of silver, phenacetin, 

 phenazone, potassium iodide and calomel that react with so many other 

 drugs that it is preferable to administer them alone, or in simple solutions 

 with a flavouring reagent or in pills. 



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