;8 



yellow colour. The common frankincense of the shops is probably no other than this resin, or, at least, the 

 latter is in general mixed with the former, and becomes an ingredient in the Emplastrum Thuris composihim, 

 and EmpL Ladani compositum, of the London Pharmacop(ma, applications employed as corroborants and 

 con Stringent s, but useful chiefly from their mechanical properties, by which considerable support is afforded 

 to the integuments whereon they are laid. 



BOILED RESIN. 



CHesina abiegna coctaj. 



Piw Burgundica, Phai'm. Lond. &c. , ■ 



Poix-grasse, of the French. 



Burgundy Pitch. 



J F ■ 



This substance is of a close consistence, but ralher soft, of a reddish brown colour, and not unpleasant 

 smell. The shops are supplied with it chiefly from Saxony, where, however, many adulterations take place, 

 and, in this country, it is to be suspected that a preparation of the common turpentine is sometimes substi- 

 tuted for it. 



The genuine Burgundy Pitch is prepared from the resinous juice of the Norway Spruce, which is yielded 

 by that tree from the month of April to September, from the effect of incisions made in the bark. In the 

 operation of cutting, the wood is left imtouched, for the juice exudes chiefly hova between the bark and the 

 wood, and in small quantities from the former alone, but not at all from the latter. It fixes almost imme- 

 diately after it is freed from its lodgments, and therefore does not flow to the ground, but remains attached 

 to the tree in large tears, or flakes. This concrete matter is coHected once in a fortnight, by detaching it 

 with an instrument formed on one side like an axe, and on the other like a gorget. With this instrument 

 also the incision is renewed every time that the resin is collected. The resin of young Spruces is softer than 

 that of old ones, but it is never fluid, except in hot countries, and under considerable exposure to the sun; 

 and even in those circumstances it has not the ssme liquidity as that of the Pines properly so called. In 

 forests impenetrable to the rays of the sun, the incisions are usually made on the south side, but in different 

 situations this is not always the practice; the side most exposed to rain is never subjected to incisions. If 

 only one incision be made in a spruce, there will be a supply of resin from twenty-five to thirty years. A 

 vigorous tree, planted in a good soil, will yield in one year thirty or forty pounds of juice. This juice 

 becomes dry enough to be put into sacks, and is thus conveyed by the peasants to places where the following 

 process is carried on, viz. The resinous substance is put, with a proper quantity of water, into large boilers; 

 a moderate fire melts it; it is then strained, under a press, through strong, close cloths, into barrels, to be 

 transported to any distance. It is rarely cast into loaves, because these would be melted by a low degree 

 of heat, and easily put out of shape. 



The above is the inode practised in the neighbourhood of Neufchatel,'' but it is different in other places, 

 as will be seen by consulting Axtius,^' Geoffroy/ &c. 



Burgundy pitch is employed only exter;ially. Formerly, it was an ingredient in a great variety of oint- 

 ments and plasters, but at present, its use is confined ])y the London College to the Emplastrum Cumini, and 

 to another which takes its name from this resin, viz. the Empl. Picis Burgundicce compositum. It forms a warm, 

 stimulant application, and sometimes creates even vesications, though, in general, a redness of the part, with 

 a gentle exudation, is the only effect observable. The cases in which the Empl. Picis Burg. comp. seems to 

 produce most good are those which may be called nervous dijspnosa; but it is serviceable likewise in coughs, 

 pains of the muscular parts of the chest, and some affections of the trachea occasioning loss of voice. It 

 should be renewed once in three or four days, and so continued for a fortnight or longer. 



^^ 



cap, 70.) pine resin was often substituted for it; and the substance now bearing that name in the shops Is seldom any other than the concrete 

 resiu described above. Dioscorides describes a mode of distinguishing the two kinds. "■' Resin (of the Pine) says he, when thrown into the fire 

 " dissipates itself in smoke, whereas frankincense burns with a brisk flame, and the odour of the latter serves to detect imposition." Some writers 

 arc of opinion that the genuine A*/3ii^vo5, Thm^ or Frankincense, is obtained from J««^/j(?rM5 Xyda, and constitutes the O^i^^mww of our shops, but 

 I cannot find any passages in ancient authors sufficiently precise to corroborate this conjecture, 



=* DuhameL Tom. i. p, i5, ' Tract, de Arb. coniJ\ p. 79. Mat. Med. T. 3. p. 437. 



