thoroughly mixed. The rest of the base is then added and the trituration 

 continued until the whole is incorporated. When completed the ointment 

 is to be dispensed in a box or jar. This should be done cautiously so as not 

 to smear the outside of the container and so as to leave a smooth finished 

 surface to the ointment itself. The spatula aided by the flame of a gas 

 or alcohol lamp over which the inverted jar is held for a moment will 

 suffice for this. 



The base selected for any ointment should be such as will fulfil the 

 purpose of the prescription, some fats being absorbed by the skin, others not. 

 It should be chosen with a view to avoiding chemical reaction between it 

 and the active constituent. As already stated the chief bases are Wool 

 Fat, Lard, and Paraffin. Their absorption by the skin and their power of 

 absorbing liquids is in the order of mention. For extemporaneous pre- 

 scriptions Wool-Fat is much more used than in the making of the official 

 ointments. 



For impressing the general system then the base should be Wool-Fat 

 or Lard, preferably the former. This used alone makes a rather stiff 

 ointment which is difficult to prepare and to apply. This may be avoided 

 by the addition of a small proportion of Lard or Olive Oil. 



For those to be used purely for their local effect, Soft Paraffin or a 

 mixture of Hard and Soft, depending upon the climate, makes the ideal 

 preparation; in cold weather less, in warm more of the Hard Paraffin is 

 used. 



The Pharmacopoeia directs the dispenser to use Yellow Paraffin if 

 colored drugs are to be dispensed and the White for those that are colour- 

 less. This is a good rule for all but those ointments to be applied to the 

 eye. White Paraffin is made by bleaching the Yellow with the aid of the 

 mineral acids and there is likely to be a trace of acid present which makes it 

 unsuited for application to the conjunctiva. For these unguents use the 

 Yellow Paraffins. The greatest precaution to obtain ointments absolutely 

 free of grit should be taken when for use in the eye. 



On the Dispensing of Plasters. The making of plasters has been so 

 completely passed ovei to the manufacturing pharmacist that it seems need- 

 less to discuss the subject. Almost any formula can be had already spread 

 by machinery with such art that the unskilled hand may not hope to obtain 

 such perfect results from a pharmaceutical, let alone from the thera- 

 peutical, standpoint. 



BOTTLES. Those used for dispensing may be had in plain or variously 

 coloured glass and of oval, round, or square shape. Medicines for in- 

 ternal use are commonly dispensed in flint or colourless bottles which are 

 somewhat more expensive than bottles made of green glass but the better 

 appearance makes ample return for the additional cost. Amber and blue 

 glass bottles are in frequent use for sending out poisons and also for storing 

 solutions which may be affected deleteriously by actinic light. Vials, for 



