50 VEGETABLE DRUGS WITHOUT ORGANIC STRUCTURE. 



comparison with six given by the first or virgin dip. 

 Scrapings are even less rich in oil, giving one to two 

 gallons to the barrel. 



In its crude liquid state it is rarely seen on the market, 

 but in its more solid form it consists of yellowish, 

 opaque, tough, sticky masses; when cold, crumbly and 

 brittle. The odor is peculiar, the taste bitter, acrid, 

 and somewhat aromatic. Purer kinds are apt to be 

 whiter ; the less valuable ones yellowish to brownish and 

 blackish, with much chip and scrapings. 



The resin in the tree is dissolved in the oil and is 

 formed in special secretory passages by the metamor- 

 phosis of the lining cells of these passages. 



Chemistry. — Turpentine is a resin dissolved in ethereal 

 oil. This oil of turpentine will vary from 15 to 30 

 per cent. ; the resin or rosin of commerce (Colopho- 

 nium) ranging from 60 to 80 per cent. ; water, 5 to 10 per 

 cent., holding bitter stuff in solution, precipitated by tan- 

 nic acid; small quantities of abietinic acid (C^^Hg^O^). 



TEREBINTHINA VENETIA. VENICE TURPENTINE. 



Venice turpentine is derived from the European larch, 

 Larix Europea, by boring holes to the center, from 

 which the resin slowly flows. It was handled in the 

 tenth century by the Venetians, hence the name. The 

 tree is native throughout the greater part of Europe, 

 but the parts where it is much used are southern France, 

 northern Italy, a little in the southern Tyrol, and much 

 in Styria. 



The holes are plugged during the winter, but in the 

 following spring the plugs are withdrawn and more 

 oleoresin collected, the process being repeated yearly. 



Description. — It occurs in clear to yellowish and brown- 

 ish masses, transparent in the finer grades, after being 

 kept some time apt to show slight fluorescence. Solidi- 

 fies slowly, non-crystalline. The odor is terebinthinate 



