PIX LIQUIDA C19 



Maly is of opinion that the same amorphous resin occurs in all the 

 ConifercB, and that it yields by hydration the same acid, namely Ahietic, 

 which has been described by former chemists as Pinic, Silvic, and 

 Pimaric acids, all of which indeed are admitted to have the same com- 

 position. We must however remember that several sorts of turpentine, 

 as Canada Balsam, appear incapable, according to our experiments, of 

 yielding any crystalline resinoid compound whatever; and that their 

 amorphous resin being but partially soluble is certainly not a homo- 

 geneous substance. 



The crystals as formed naturally in the common turpentines do not 

 exhibit precisely the same forms as those obtained artificially when the 

 resins are agitated with warm diluted alcohol, as in the preparation of 

 ahietic acid. As to Pimaric Acid, we have prepared it in quantity 

 from galipot, the resin of Pmiis Pinaster, but have ahyays^ found its 

 crystalline character entirely different from that of abietic acid.^ 



We are inclined, therefore, to think that the composition of the 



1 



^ 



the remarkable 



variety of their essential oils is a fact which seems iu favour of our 



\i&\Y. 



Uses— Burgundy pitch is prescribed as an ingredient of plasters, 

 and thus employed is useful as a mild stimulant. In Germany it has 

 some economic applications, one of which is the lining of beer casks, 

 for which purpose a composition is used called Braiierpech (brewers' 

 pitch), made by mixing it with colophony or galipot 



Adulteration— No drug is the subject of more adulteration than 

 Burgundy pitch, so much so that the very name is understood by some 

 pharmacologists to be that of a manufactured compound. The substance 

 commonly sold in England is made by melting together colophony 

 with palm oil or some other fat, water being stirred in to render the 

 mixture opaque. In appearance it is very variable, different samples 

 ])resenting different shades of bright or dull yellow or yellowish-brown. 

 Many when broken exhibit numerous cavities contammg au' or water ; 

 all are more or less opaque, becoming in time transparent on the surface 

 ty the loss of water. Artificial Burgundy pitch is offered for sale in 

 bladders; it has a weak terebinth inous odour, and is devoid ot tne 

 peculiar fragrance of the genuine. The presence of a fatty oil is easily 

 discovered by treatment with double its weight of glacial acetic acid, 

 which forms a turbid mixture, separating by repose into two layers, tne 

 upper being oily. 



PIX LIQUIDA. 



V^ood Tar; F. Goudron vegetal, Poix liquide; G. Holztheer, 



FicJdentheev. 



Botanical Origin— Tar is obtained by submitting the wood of the 

 stems and roots of coniferous trees to dry or destructive distillation. 

 That found in commerce is produced in Northern Europe, chiefly from 

 two species, namely Phius sllvestins L. and P. Ledebourii Endh {Larix 

 sihiHca Ledeb.). The^e trees constitute the vast forests of Arctic 

 Europe and Asia. 



^ Jahreshericht of Wiggers and Husemann for 1867. 37. 



