ORGANIC POISONS AND DEUGS 129 



TURPENTINE, CAMPHOR, AND ESSENTIAL OILS. 



Occurrence. — Under this heading may be conveniently 

 collected those cases of poisoning arising either from oils, 

 essences, or the plants which contain them. The general 

 effect of this class is irritant, and after absorption narcotic 

 or paralysant. 



Turpentine is the hydrocarbon, or mixture of hydro- 

 carbons, distilled from the oleoresin of the pine, Pinus sylves- 

 tris, etc., of the order Conifera. Turpentines are optically 

 active, rotating the plane of polarised light, and this affords 

 an excellent qualitative guide. Thus, in examining a tar- 

 oil preparation the obtaining of an active distillate indicates 

 turpentine or wood tar, as distinguished from coal tar. 

 Oil of savin is chemically a turpentine, and is contained to 

 the extent of about 3 per cent, in the tops of the common 

 savin {Juniperus sabina — Coniferce), a cultivated evergreen 

 shrub, commonly credited with abortive properties. Savin 

 possesses a very characteristic acrid taste and smell, and 

 probably contains other principles than turpentine, for its 

 activity is certainly greater. Savin, American red, or pencil, 

 cedar {Juniperus virginiana), and Wellingtonia sequoia, are 

 conifers not indigenous to Britain, but cultivated in our 

 gardens, and must be held liable to be possible causes of 

 poisoning. Like savin, the two last-named species contain 

 essential turpentine oils. 



The rue (Kuta graveolens) is an exotic member of the 

 GeraniacecB, cultivated in this country, and which contains, 

 according to Cornevin, an essential oil, and an acid i-utinic 

 acid. 



Camphor is a neutral, crystalline, volatile solid of the class 

 of ketones allied to turpentine, and is obtained from the 

 evergreen camphor laurel, native to East Asia. Artificial 

 camphor is prepared by the action of dry hydrochloric acid 

 gas on turpentine. 



The common tansy {Tanacetum vulgar e of the Compositce), 

 allied to the Artemisia, is a herb often used in this country 



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