66 



UNGUENTA. 



EMPLASTRA. 



Other official Ointments, but of limited utility, are: Ung. Acidi Borici, 10% ; 

 Ung. Acidi Tannici, 20%; Ung. Diachylon, of pharmaceutical interest chiefly; Ung. 

 Gallse, 20%; Ung. Hydrargyri, 50*70, a base; Ung. Hydrargyri Nitratis, j%, citrine 

 ointment; Ung. lodi, 4% ', Ung. lodoformi, 10%, an abomination; Ung. Phenolis, 2%, 

 formerly in much favor; Ung. Stramonii, 20%, superfluous. 



CERATA. 



Cerates are unctuous fatty preparations, similar to ointments, but having a higher 

 melting point, and not liquefying at the body temperature. 



Prepare the official Ceratum as follows: By the heat of a water bath melt 30 

 Gm. white wax, add 70 Gm. benzoinated lard ; continue heat until all is melted ; strain 

 through thin cheesecloth, and stir constantly until the mixture congeals. (For hot 

 localities a greater percentage of wax may be necessary.) 



How does the consistency of the Cerate compare with an ointment ? 



Two other Cerates are official : Ceratum Cantharidis, which belongs to a dis- 

 carded therapeutics ; and Ceratum Resinae, used in making Linimentum Terebinthinse. 



EMPLASTRA. 



Plasters are solid, adhesive preparations, spread on some fabric, and usually 

 requiring warming before being applied to the body. 



Prepare as follows a satisfactory substitute for the official Emplastrum Sinapis: 

 To 8 Gm. flour add 4 Gm. mustard; mix thoroughly, then add just enough warm 

 water (not hot) to make a soft smooth paste. Spread this on heavy paper or on 

 cottoncloth. 



Bind some of your prepared Mustard Plaster on the flexor surface of your fore- 

 arm, and leave it there until distinctly sharp sensations are perceived. Remove plaster, 



and examine appearance of the skin. Report: -'. 



Time taken for effect : 



Nature of effect : 



Duration of effect : 



The following Plasters are official : 



