Pix LIQUID A. 349 



without bitterness ; free from vesicles ; gives off no water when 

 heated. 



Composition. Burgundy pitch consists of various resinous 

 acids, as in ordinary resin, combined with oil of turpentine. A 

 special volatile oil imparts to it its odour. 



Preparation. 



Emplastrum Picis. 1 in 2. 

 Pix Burgundica is also contained in Emplastrum Ferri. 



ACTION AND USES. 



Burgundy pitch has a mildly stimulant action on the skin, 

 and is used only for making plasters. 



Fix Liquida TAR. A bituminous liquid ob- 

 tained from the wood of Pinus sylvestris and other 

 pines by destructive distillation. 



Characters. Thick, viscid, brownish-black, of a well-known 

 peculiar aromatic odour. Water agitated with it acquires a' 

 pale-brown colour, sharp empyreumatic taste, and acid reaction. 



Composition. Tar is a variable mixture of creasote, phenol 

 (carbolic acid), toluol, xylol, acetic acid, turpentine, resin, etc. 



Dose. 20 to 60 min. in pill. 



Preparation. 

 Unguentum Picis Liquidse. 5 in 7. 



ACTION AND USES. 



Tar, being a compound of creasote, carbolic acid, and 

 other substances, possesses an action very similar to the first 

 two of these bodies, to which the student is referred. Its 

 exact composition being variable, the action of tar is uncertain; 

 and internally it is now but little employed. 



Externally, it is more valuable than either of its important 

 constituents, as a vascular stimulant and alterative in dry skin 

 diseases, such as chronic eczema and psoriasis; and as a nervous 

 sedative in prurigo and other kinds of itching. 



Internally, tar may be given in pills, in capsules, or as 

 tar-water, made by shaking up a pint of tar with half-a-gallon 

 of water, and decanting after settlement a very popular 

 panacea a hundred years ago. Tar may still be used as a 

 disinfectant in the stomach and bowels (see Creasotum, page 172), 



