COLLODIA. FLUIDEXTRACTA. 69 



this mixture until the pyroxylin is dissolved. Cork the bottle tightly, setting- it aside 

 until the liquid has cleared; then decant the clear portion, place in a suitable bottle, and 

 cork tightly. 



All these operations must be conducted away from the vicinity of any flame. 



Prepare the official Collodium Flexile as follows : Tare a small bottle, and into it 

 place 19 Gm. Collodion, 0.4 Gm. camphor, and 0.6 Gm. castor oil; shake the mixture 

 until the camphor is dissolved. 



This preparation should be kept in well-stoppered bottles, in a cool place, and well 

 removed from the fire. 



Properties of Collodia, 



Paint one knuckle with Collodion, and an adjacent knuckle with Flexible Col- 

 lodion. On flexor surface of forearm, paint comparative areas with the two in the 

 same way. 



Collodium : 

 Sample .... 



Appearance 



Color 

 Odor . 



Flexibility 



Adhesiveness _ 



Contraction ... 



Collodium Flexile : 

 Sample 



Appearance 

 Color .. 



Odor. 



Flexibility 



Adhesiveness 

 Contraction ... 



Collodia are used as adhesive protectives; also to render cotton dressings more 

 concrete and impervious. They are being in part supplanted by the new flexible 

 paraffin dressings. 



There is one other official Collodion: Collodium Cantharidatum. This is an 

 obsolescent preparation, well deserving complete discard. 



FLUIDEXTRACTA. 



Fluidextracts are liquid preparations of vegetable drugs, so made that I mil of 

 the liquid preparation represents the medicinal activity of I Gm. of the powdered drug. 



With four exceptions (Cascara, Frangula, Glycyrrhiza, and Triticum), they are 

 extracts 'of those vegetable principles that are soluble in alcohol. The four exceptions 

 are more akin to infusions, being water extracts ; but they each have alcohol added as 

 a preservative. 



There are four different methods of preparing Fluidextracts : three by percola- 

 tion, and one by percolation and infusion. In making these preparations, the rate of 

 percolation should not exceed 10 drops a minute for the reserved portion, and 20 drops 

 a minute thereafter. It is usually assumed that 3000 mils of percolate will exhaust 

 1000 Gm. powdered drug. 



Prepare the official Fluidextractum Podophylli by "Type Process A" as follows: 

 Place 100 Gm. podophyllum, in No. 40 powder, in a mortar; render it evenly and 

 decidedly damp with alcohol ; place it in a percolator, and leave it tightly covered for 

 6 hours. Then saturate it with alcohol, and when the alcohol begins to drip from the 



