ABIES SPRUCE. 257 



viscid, somewhat opalescent liquid, of an agreeable odor and a pungent, 

 bitterish taste. Exposed to the air for a length of time it concretes, and 

 forms a tough mass which is brittle when cold. It consists of volatile oil 

 and resin. The former is separated by distillation, and is the spirit of 

 turpentine of commerce, while the latter is the non-volatile residue, com- 

 mercially known as rosin. Tar is an empyreumatic oleoresin of very com- 

 plex composition, containing acetic acid, methylic alcohol, creasote, car- 

 bolic acid, etc. 



Preparations. — Of turpentine : Oleum terebinthinse — oil of turpentine, 

 resina — resin. Preparations of oil of turpentine : Linamentum canthari- 

 dis — ^antharides liniment ; linamentum terebinthinse — turpentine lini- 

 ment. Preparations of resin : Ceratum resinae — resin cerate ; emplastrum 

 resinse — resin plaster. Preparations of tar : Syrupus picis liquidae — syrup 

 of tar ; unguentum picis liquidae — tar ointment. — United States Pharma- 

 copoeia. 



Medical Properties and Uses. — Crude turpentine is seldom or never 

 used internally at the present day ; since its virtues are believed to reside 

 chiefly in its essential oil, this is almost universally employed instead. Oil 

 of turpentine is stimulant, diuretic, anthelmintic, and, in large doses, cathar- 

 tic ; externally it is rubefacient and mildly vesicant. In small, frequently 

 repeated doses it stimulates the kidneys, augments the secretion of urine, 

 and occasionally produces strangury and hsematuria. In large doses it 

 produces vertigo, nausea, and often brisk catharsis. It is used in a great 

 variety of cases. Like other terebinthinate medicines it is often employed 

 in the later stages of gonorrhoea, and in other catarrhal affections. In 

 typhoid fever, and in other affections where tympanites is a prominent and 

 distressing symptom, it often affords great relief ; and, indeed, in low ty- 

 phoid conditions generally its employment is commonly very satisfactory. 

 Its controlling influence in passive hemorrhages has also long been recog- 

 nized and made use of. As a vermifuge it often enters into the composi- 

 tion of draughts for the expulsion of taenia. Externally, alone or in com- 

 bination, it is' largely employed as a rubefacient. 



Resin is employed as an ingredient of plasters and cerates, to which it 

 gives consistence and adhesiveness, without adding sensibly to their ac- 

 tivity. 



The medicinal properties of tar are similar to those of turpentine, 

 modified, however, to some extent by the purely empyreumatic bodies 

 which it contains. It is used internally and by inhalation in chronic ca- 

 tarrhal affections, and externally in a variety of cutaneous diseases. 



ABIES.— SrRUCE. 



Character of the Genus. — Sterile catkins scattered or clustered in the 

 axils of the leaves of the preceding year ; fertile catkins lateral or terminal 

 on the branches of the preceding year ; both appearing in spring, the cones 



